diff --git a/package.json b/package.json
index 3fd7703afb..3d1fb535c0 100644
--- a/package.json
+++ b/package.json
@@ -89,11 +89,11 @@
     "prop-types": "^15.5.8",
     "qrcode": "^1.4.4",
     "qs": "^6.6.0",
+    "re-resizable": "^6.5.2",
     "react": "^16.9.0",
     "react-beautiful-dnd": "^4.0.1",
     "react-dom": "^16.9.0",
     "react-focus-lock": "^2.2.1",
-    "react-resizable": "^1.10.1",
     "react-transition-group": "^4.4.1",
     "resize-observer-polyfill": "^1.5.0",
     "sanitize-html": "^1.18.4",
@@ -122,6 +122,7 @@
     "@types/classnames": "^2.2.10",
     "@types/counterpart": "^0.18.1",
     "@types/flux": "^3.1.9",
+    "@types/linkifyjs": "^2.1.3",
     "@types/lodash": "^4.14.152",
     "@types/modernizr": "^3.5.3",
     "@types/node": "^12.12.41",
@@ -129,6 +130,7 @@
     "@types/react": "^16.9",
     "@types/react-dom": "^16.9.8",
     "@types/react-transition-group": "^4.4.0",
+    "@types/sanitize-html": "^1.23.3",
     "@types/zxcvbn": "^4.4.0",
     "babel-eslint": "^10.0.3",
     "babel-jest": "^24.9.0",
diff --git a/res/css/structures/_LeftPanel2.scss b/res/css/structures/_LeftPanel2.scss
index a73658d916..eaa22a3efa 100644
--- a/res/css/structures/_LeftPanel2.scss
+++ b/res/css/structures/_LeftPanel2.scss
@@ -121,6 +121,21 @@ $tagPanelWidth: 70px; // only applies in this file, used for calculations
             }
         }
 
+        .mx_LeftPanel2_roomListWrapper {
+            display: flex;
+            flex-grow: 1;
+            overflow: hidden;
+            min-height: 0;
+
+            &.stickyBottom {
+                padding-bottom: 32px;
+            }
+
+            &.stickyTop {
+                padding-top: 32px;
+            }
+        }
+
         .mx_LeftPanel2_actualRoomListContainer {
             flex-grow: 1; // fill the available space
             overflow-y: auto;
diff --git a/res/css/views/rooms/_RoomSublist2.scss b/res/css/views/rooms/_RoomSublist2.scss
index 0e76152f86..30389a4ec5 100644
--- a/res/css/views/rooms/_RoomSublist2.scss
+++ b/res/css/views/rooms/_RoomSublist2.scss
@@ -54,9 +54,6 @@ limitations under the License.
             max-width: 100%;
             z-index: 2; // Prioritize headers in the visible list over sticky ones
 
-            // Set the same background color as the room list for sticky headers
-            background-color: $roomlist2-bg-color;
-
             // Create a flexbox to make ordering easy
             display: flex;
             align-items: center;
@@ -203,15 +200,16 @@ limitations under the License.
             // Update the render() function for RoomSublist2 if these change
             // Update the ListLayout class for minVisibleTiles if these change.
             //
-            // At 24px high and 8px padding on the top this equates to 0.65 of
+            // At 24px high, 8px padding on the top and 4px padding on the bottom  this equates to 0.73 of
             // a tile due to how the padding calculations work.
             height: 24px;
             padding-top: 8px;
+            padding-bottom: 4px;
 
             // We force this to the bottom so it will overlap rooms as needed.
             // We account for the space it takes up (24px) in the code through padding.
             position: absolute;
-            bottom: 4px; // the height of the resize handle
+            bottom: 0; // the height of the resize handle
             left: 0;
             right: 0;
 
@@ -253,24 +251,26 @@ limitations under the License.
         // Class name comes from the ResizableBox component
         // The hover state needs to use the whole sublist, not just the resizable box,
         // so that selector is below and one level higher.
-        .react-resizable-handle {
+        .mx_RoomSublist2_resizerHandle {
             cursor: ns-resize;
             border-radius: 3px;
 
-            // Update RESIZE_HANDLE_HEIGHT if this changes
-            height: 4px;
+            // Override styles from library
+            width: unset !important;
+            height: 4px !important; // Update RESIZE_HANDLE_HEIGHT if this changes
 
             // This is positioned directly below the 'show more' button.
             position: absolute;
-            bottom: 0;
+            bottom: 0 !important; // override from library
 
             // Together, these make the bar 64px wide
-            left: calc(50% - 32px);
-            right: calc(50% - 32px);
+            // These are also overridden from the library
+            left: calc(50% - 32px) !important;
+            right: calc(50% - 32px) !important;
         }
 
         &:hover, &.mx_RoomSublist2_hasMenuOpen {
-            .react-resizable-handle {
+            .mx_RoomSublist2_resizerHandle {
                 opacity: 0.8;
                 background-color: $primary-fg-color;
             }
diff --git a/res/css/views/rooms/_RoomTile2.scss b/res/css/views/rooms/_RoomTile2.scss
index 380a3ab9c7..b9e0398e7d 100644
--- a/res/css/views/rooms/_RoomTile2.scss
+++ b/res/css/views/rooms/_RoomTile2.scss
@@ -21,6 +21,10 @@ limitations under the License.
     margin-bottom: 4px;
     padding: 4px;
 
+    // allow scrollIntoView to ignore the sticky headers, must match combined height of .mx_RoomSublist2_headerContainer
+    scroll-margin-top: 32px;
+    scroll-margin-bottom: 32px;
+
     // The tile is also a flexbox row itself
     display: flex;
 
@@ -165,6 +169,11 @@ limitations under the License.
     }
 }
 
+// do not apply scroll-margin-bottom to the sublist which will not have a sticky header below it
+.mx_RoomSublist2:last-child .mx_RoomTile2 {
+    scroll-margin-bottom: 0;
+}
+
 // We use these both in context menus and the room tiles
 .mx_RoomTile2_iconBell::before {
     mask-image: url('$(res)/img/feather-customised/bell.svg');
diff --git a/res/themes/light/css/_light.scss b/res/themes/light/css/_light.scss
index c4b4262642..8469a85bfe 100644
--- a/res/themes/light/css/_light.scss
+++ b/res/themes/light/css/_light.scss
@@ -36,7 +36,7 @@ $focus-bg-color: #dddddd;
 $accent-fg-color: #ffffff;
 $accent-color-50pct: rgba(3, 179, 129, 0.5);    //#03b381 in rgb
 $accent-color-darker: #92caad;
-$accent-color-alt: #238CF5;
+$accent-color-alt: #238cf5;
 
 $selection-fg-color: $primary-bg-color;
 
@@ -46,8 +46,8 @@ $focus-brightness: 105%;
 $warning-color: $notice-primary-color; // red
 $orange-warning-color: #ff8d13; // used for true warnings
 // background colour for warnings
-$warning-bg-color: #DF2A8B;
-$info-bg-color: #2A9EDF;
+$warning-bg-color: #df2a8b;
+$info-bg-color: #2a9edf;
 $mention-user-pill-bg-color: $warning-color;
 $other-user-pill-bg-color: rgba(0, 0, 0, 0.1);
 
@@ -71,7 +71,7 @@ $tagpanel-bg-color: #27303a;
 $plinth-bg-color: $secondary-accent-color;
 
 // used by RoomDropTarget
-$droptarget-bg-color: rgba(255,255,255,0.5);
+$droptarget-bg-color: rgba(255, 255, 255, 0.5);
 
 // used by AddressSelector
 $selected-color: $secondary-accent-color;
@@ -157,18 +157,18 @@ $rte-group-pill-color: #aaa;
 
 $topleftmenu-color: #212121;
 $roomheader-color: #45474a;
-$roomheader-addroom-bg-color: #91A1C0;
+$roomheader-addroom-bg-color: #91a1c0;
 $roomheader-addroom-fg-color: $accent-fg-color;
-$tagpanel-button-color: #91A1C0;
-$roomheader-button-color: #91A1C0;
-$groupheader-button-color: #91A1C0;
-$rightpanel-button-color: #91A1C0;
-$composer-button-color: #91A1C0;
+$tagpanel-button-color: #91a1c0;
+$roomheader-button-color: #91a1c0;
+$groupheader-button-color: #91a1c0;
+$rightpanel-button-color: #91a1c0;
+$composer-button-color: #91a1c0;
 $roomtopic-color: #9e9e9e;
 $eventtile-meta-color: $roomtopic-color;
 
 $composer-e2e-icon-color: #c9ced6;
-$header-divider-color: #91A1C0;
+$header-divider-color: #91a1c0;
 
 // ********************
 
@@ -184,11 +184,11 @@ $roomsublist2-divider-color: $primary-fg-color;
 
 $roomtile2-preview-color: #9e9e9e;
 $roomtile2-default-badge-bg-color: #61708b;
-$roomtile2-selected-bg-color: #FFF;
+$roomtile2-selected-bg-color: #fff;
 
 $presence-online: $accent-color;
-$presence-away: orange; // TODO: Get color
-$presence-offline: #E3E8F0;
+$presence-away: #d9b072;
+$presence-offline: #e3e8f0;
 
 // ********************
 
diff --git a/src/@types/common.ts b/src/@types/common.ts
index 9109993541..a24d47ac9e 100644
--- a/src/@types/common.ts
+++ b/src/@types/common.ts
@@ -17,3 +17,4 @@ limitations under the License.
 // Based on https://stackoverflow.com/a/53229857/3532235
 export type Without<T, U> = {[P in Exclude<keyof T, keyof U>] ? : never};
 export type XOR<T, U> = (T | U) extends object ? (Without<T, U> & U) | (Without<U, T> & T) : T | U;
+export type Writeable<T> = { -readonly [P in keyof T]: T[P] };
diff --git a/src/@types/polyfill.ts b/src/@types/polyfill.ts
new file mode 100644
index 0000000000..3ce05d9c2f
--- /dev/null
+++ b/src/@types/polyfill.ts
@@ -0,0 +1,38 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// This is intended to fix re-resizer because of its unguarded `instanceof TouchEvent` checks.
+export function polyfillTouchEvent() {
+    // Firefox doesn't have touch events without touch devices being present, so create a fake
+    // one we can rely on lying about.
+    if (!window.TouchEvent) {
+        // We have no intention of actually using this, so just lie.
+        window.TouchEvent = class TouchEvent extends UIEvent {
+            public get altKey(): boolean { return false; }
+            public get changedTouches(): any { return []; }
+            public get ctrlKey(): boolean { return false; }
+            public get metaKey(): boolean { return false; }
+            public get shiftKey(): boolean { return false; }
+            public get targetTouches(): any { return []; }
+            public get touches(): any { return []; }
+            public get rotation(): number { return 0.0; }
+            public get scale(): number { return 0.0; }
+            constructor(eventType: string, params?: any) {
+                super(eventType, params);
+            }
+        };
+    }
+}
diff --git a/src/HtmlUtils.js b/src/HtmlUtils.tsx
similarity index 83%
rename from src/HtmlUtils.js
rename to src/HtmlUtils.tsx
index 34e9e55d25..6dba041685 100644
--- a/src/HtmlUtils.js
+++ b/src/HtmlUtils.tsx
@@ -17,10 +17,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-'use strict';
-
-import ReplyThread from "./components/views/elements/ReplyThread";
-
 import React from 'react';
 import sanitizeHtml from 'sanitize-html';
 import * as linkify from 'linkifyjs';
@@ -28,12 +24,13 @@ import linkifyMatrix from './linkify-matrix';
 import _linkifyElement from 'linkifyjs/element';
 import _linkifyString from 'linkifyjs/string';
 import classNames from 'classnames';
-import {MatrixClientPeg} from './MatrixClientPeg';
+import EMOJIBASE_REGEX from 'emojibase-regex';
 import url from 'url';
 
-import EMOJIBASE_REGEX from 'emojibase-regex';
+import {MatrixClientPeg} from './MatrixClientPeg';
 import {tryTransformPermalinkToLocalHref} from "./utils/permalinks/Permalinks";
 import {SHORTCODE_TO_EMOJI, getEmojiFromUnicode} from "./emoji";
+import ReplyThread from "./components/views/elements/ReplyThread";
 
 linkifyMatrix(linkify);
 
@@ -64,7 +61,7 @@ const PERMITTED_URL_SCHEMES = ['http', 'https', 'ftp', 'mailto', 'magnet'];
  * need emojification.
  * unicodeToImage uses this function.
  */
-function mightContainEmoji(str) {
+function mightContainEmoji(str: string) {
     return SURROGATE_PAIR_PATTERN.test(str) || SYMBOL_PATTERN.test(str);
 }
 
@@ -74,7 +71,7 @@ function mightContainEmoji(str) {
  * @param {String} char The emoji character
  * @return {String} The shortcode (such as :thumbup:)
  */
-export function unicodeToShortcode(char) {
+export function unicodeToShortcode(char: string) {
     const data = getEmojiFromUnicode(char);
     return (data && data.shortcodes ? `:${data.shortcodes[0]}:` : '');
 }
@@ -85,7 +82,7 @@ export function unicodeToShortcode(char) {
  * @param {String} shortcode The shortcode (such as :thumbup:)
  * @return {String} The emoji character; null if none exists
  */
-export function shortcodeToUnicode(shortcode) {
+export function shortcodeToUnicode(shortcode: string) {
     shortcode = shortcode.slice(1, shortcode.length - 1);
     const data = SHORTCODE_TO_EMOJI.get(shortcode);
     return data ? data.unicode : null;
@@ -100,7 +97,7 @@ export function processHtmlForSending(html: string): string {
     }
 
     let contentHTML = "";
-    for (let i=0; i < contentDiv.children.length; i++) {
+    for (let i = 0; i < contentDiv.children.length; i++) {
         const element = contentDiv.children[i];
         if (element.tagName.toLowerCase() === 'p') {
             contentHTML += element.innerHTML;
@@ -122,12 +119,19 @@ export function processHtmlForSending(html: string): string {
  * Given an untrusted HTML string, return a React node with an sanitized version
  * of that HTML.
  */
-export function sanitizedHtmlNode(insaneHtml) {
+export function sanitizedHtmlNode(insaneHtml: string) {
     const saneHtml = sanitizeHtml(insaneHtml, sanitizeHtmlParams);
 
     return <div dangerouslySetInnerHTML={{ __html: saneHtml }} dir="auto" />;
 }
 
+export function sanitizedHtmlNodeInnerText(insaneHtml: string) {
+    const saneHtml = sanitizeHtml(insaneHtml, sanitizeHtmlParams);
+    const contentDiv = document.createElement("div");
+    contentDiv.innerHTML = saneHtml;
+    return contentDiv.innerText;
+}
+
 /**
  * Tests if a URL from an untrusted source may be safely put into the DOM
  * The biggest threat here is javascript: URIs.
@@ -136,7 +140,7 @@ export function sanitizedHtmlNode(insaneHtml) {
  * other places we need to sanitise URLs.
  * @return true if permitted, otherwise false
  */
-export function isUrlPermitted(inputUrl) {
+export function isUrlPermitted(inputUrl: string) {
     try {
         const parsed = url.parse(inputUrl);
         if (!parsed.protocol) return false;
@@ -147,9 +151,9 @@ export function isUrlPermitted(inputUrl) {
     }
 }
 
-const transformTags = { // custom to matrix
+const transformTags: sanitizeHtml.IOptions["transformTags"] = { // custom to matrix
     // add blank targets to all hyperlinks except vector URLs
-    'a': function(tagName, attribs) {
+    'a': function(tagName: string, attribs: sanitizeHtml.Attributes) {
         if (attribs.href) {
             attribs.target = '_blank'; // by default
 
@@ -162,7 +166,7 @@ const transformTags = { // custom to matrix
         attribs.rel = 'noreferrer noopener'; // https://mathiasbynens.github.io/rel-noopener/
         return { tagName, attribs };
     },
-    'img': function(tagName, attribs) {
+    'img': function(tagName: string, attribs: sanitizeHtml.Attributes) {
         // Strip out imgs that aren't `mxc` here instead of using allowedSchemesByTag
         // because transformTags is used _before_ we filter by allowedSchemesByTag and
         // we don't want to allow images with `https?` `src`s.
@@ -176,7 +180,7 @@ const transformTags = { // custom to matrix
         );
         return { tagName, attribs };
     },
-    'code': function(tagName, attribs) {
+    'code': function(tagName: string, attribs: sanitizeHtml.Attributes) {
         if (typeof attribs.class !== 'undefined') {
             // Filter out all classes other than ones starting with language- for syntax highlighting.
             const classes = attribs.class.split(/\s/).filter(function(cl) {
@@ -186,7 +190,7 @@ const transformTags = { // custom to matrix
         }
         return { tagName, attribs };
     },
-    '*': function(tagName, attribs) {
+    '*': function(tagName: string, attribs: sanitizeHtml.Attributes) {
         // Delete any style previously assigned, style is an allowedTag for font and span
         // because attributes are stripped after transforming
         delete attribs.style;
@@ -220,7 +224,7 @@ const transformTags = { // custom to matrix
     },
 };
 
-const sanitizeHtmlParams = {
+const sanitizeHtmlParams: sanitizeHtml.IOptions = {
     allowedTags: [
         'font', // custom to matrix for IRC-style font coloring
         'del', // for markdown
@@ -247,16 +251,16 @@ const sanitizeHtmlParams = {
 };
 
 // this is the same as the above except with less rewriting
-const composerSanitizeHtmlParams = Object.assign({}, sanitizeHtmlParams);
-composerSanitizeHtmlParams.transformTags = {
-    'code': transformTags['code'],
-    '*': transformTags['*'],
+const composerSanitizeHtmlParams: sanitizeHtml.IOptions = {
+    ...sanitizeHtmlParams,
+    transformTags: {
+        'code': transformTags['code'],
+        '*': transformTags['*'],
+    },
 };
 
-class BaseHighlighter {
-    constructor(highlightClass, highlightLink) {
-        this.highlightClass = highlightClass;
-        this.highlightLink = highlightLink;
+abstract class BaseHighlighter<T extends React.ReactNode> {
+    constructor(public highlightClass: string, public highlightLink: string) {
     }
 
     /**
@@ -270,47 +274,49 @@ class BaseHighlighter {
      * returns a list of results (strings for HtmlHighligher, react nodes for
      * TextHighlighter).
      */
-    applyHighlights(safeSnippet, safeHighlights) {
+    public applyHighlights(safeSnippet: string, safeHighlights: string[]): T[] {
         let lastOffset = 0;
         let offset;
-        let nodes = [];
+        let nodes: T[] = [];
 
         const safeHighlight = safeHighlights[0];
         while ((offset = safeSnippet.toLowerCase().indexOf(safeHighlight.toLowerCase(), lastOffset)) >= 0) {
             // handle preamble
             if (offset > lastOffset) {
-                var subSnippet = safeSnippet.substring(lastOffset, offset);
-                nodes = nodes.concat(this._applySubHighlights(subSnippet, safeHighlights));
+                const subSnippet = safeSnippet.substring(lastOffset, offset);
+                nodes = nodes.concat(this.applySubHighlights(subSnippet, safeHighlights));
             }
 
             // do highlight. use the original string rather than safeHighlight
             // to preserve the original casing.
             const endOffset = offset + safeHighlight.length;
-            nodes.push(this._processSnippet(safeSnippet.substring(offset, endOffset), true));
+            nodes.push(this.processSnippet(safeSnippet.substring(offset, endOffset), true));
 
             lastOffset = endOffset;
         }
 
         // handle postamble
         if (lastOffset !== safeSnippet.length) {
-            subSnippet = safeSnippet.substring(lastOffset, undefined);
-            nodes = nodes.concat(this._applySubHighlights(subSnippet, safeHighlights));
+            const subSnippet = safeSnippet.substring(lastOffset, undefined);
+            nodes = nodes.concat(this.applySubHighlights(subSnippet, safeHighlights));
         }
         return nodes;
     }
 
-    _applySubHighlights(safeSnippet, safeHighlights) {
+    private applySubHighlights(safeSnippet: string, safeHighlights: string[]): T[] {
         if (safeHighlights[1]) {
             // recurse into this range to check for the next set of highlight matches
             return this.applyHighlights(safeSnippet, safeHighlights.slice(1));
         } else {
             // no more highlights to be found, just return the unhighlighted string
-            return [this._processSnippet(safeSnippet, false)];
+            return [this.processSnippet(safeSnippet, false)];
         }
     }
+
+    protected abstract processSnippet(snippet: string, highlight: boolean): T;
 }
 
-class HtmlHighlighter extends BaseHighlighter {
+class HtmlHighlighter extends BaseHighlighter<string> {
     /* highlight the given snippet if required
      *
      * snippet: content of the span; must have been sanitised
@@ -318,28 +324,23 @@ class HtmlHighlighter extends BaseHighlighter {
      *
      * returns an HTML string
      */
-    _processSnippet(snippet, highlight) {
+    protected processSnippet(snippet: string, highlight: boolean): string {
         if (!highlight) {
             // nothing required here
             return snippet;
         }
 
-        let span = "<span class=\""+this.highlightClass+"\">"
-            + snippet + "</span>";
+        let span = `<span class="${this.highlightClass}">${snippet}</span>`;
 
         if (this.highlightLink) {
-            span = "<a href=\""+encodeURI(this.highlightLink)+"\">"
-                +span+"</a>";
+            span = `<a href="${encodeURI(this.highlightLink)}">${span}</a>`;
         }
         return span;
     }
 }
 
-class TextHighlighter extends BaseHighlighter {
-    constructor(highlightClass, highlightLink) {
-        super(highlightClass, highlightLink);
-        this._key = 0;
-    }
+class TextHighlighter extends BaseHighlighter<React.ReactNode> {
+    private key = 0;
 
     /* create a <span> node to hold the given content
      *
@@ -348,13 +349,12 @@ class TextHighlighter extends BaseHighlighter {
      *
      * returns a React node
      */
-    _processSnippet(snippet, highlight) {
-        const key = this._key++;
+    protected processSnippet(snippet: string, highlight: boolean): React.ReactNode {
+        const key = this.key++;
 
-        let node =
-            <span key={key} className={highlight ? this.highlightClass : null}>
-                { snippet }
-            </span>;
+        let node = <span key={key} className={highlight ? this.highlightClass : null}>
+            { snippet }
+        </span>;
 
         if (highlight && this.highlightLink) {
             node = <a key={key} href={this.highlightLink}>{ node }</a>;
@@ -364,6 +364,20 @@ class TextHighlighter extends BaseHighlighter {
     }
 }
 
+interface IContent {
+    format?: string;
+    formatted_body?: string;
+    body: string;
+}
+
+interface IOpts {
+    highlightLink?: string;
+    disableBigEmoji?: boolean;
+    stripReplyFallback?: boolean;
+    returnString?: boolean;
+    forComposerQuote?: boolean;
+    ref?: React.Ref<any>;
+}
 
 /* turn a matrix event body into html
  *
@@ -378,7 +392,7 @@ class TextHighlighter extends BaseHighlighter {
  * opts.forComposerQuote: optional param to lessen the url rewriting done by sanitization, for quoting into composer
  * opts.ref: React ref to attach to any React components returned (not compatible with opts.returnString)
  */
-export function bodyToHtml(content, highlights, opts={}) {
+export function bodyToHtml(content: IContent, highlights: string[], opts: IOpts = {}) {
     const isHtmlMessage = content.format === "org.matrix.custom.html" && content.formatted_body;
     let bodyHasEmoji = false;
 
@@ -387,9 +401,9 @@ export function bodyToHtml(content, highlights, opts={}) {
         sanitizeParams = composerSanitizeHtmlParams;
     }
 
-    let strippedBody;
-    let safeBody;
-    let isDisplayedWithHtml;
+    let strippedBody: string;
+    let safeBody: string;
+    let isDisplayedWithHtml: boolean;
     // XXX: We sanitize the HTML whilst also highlighting its text nodes, to avoid accidentally trying
     // to highlight HTML tags themselves.  However, this does mean that we don't highlight textnodes which
     // are interrupted by HTML tags (not that we did before) - e.g. foo<span/>bar won't get highlighted
@@ -471,7 +485,7 @@ export function bodyToHtml(content, highlights, opts={}) {
  * @param {object} [options] Options for linkifyString. Default: linkifyMatrix.options
  * @returns {string} Linkified string
  */
-export function linkifyString(str, options = linkifyMatrix.options) {
+export function linkifyString(str: string, options = linkifyMatrix.options) {
     return _linkifyString(str, options);
 }
 
@@ -482,7 +496,7 @@ export function linkifyString(str, options = linkifyMatrix.options) {
  * @param {object} [options] Options for linkifyElement. Default: linkifyMatrix.options
  * @returns {object}
  */
-export function linkifyElement(element, options = linkifyMatrix.options) {
+export function linkifyElement(element: HTMLElement, options = linkifyMatrix.options) {
     return _linkifyElement(element, options);
 }
 
@@ -493,7 +507,7 @@ export function linkifyElement(element, options = linkifyMatrix.options) {
  * @param {object} [options] Options for linkifyString. Default: linkifyMatrix.options
  * @returns {string}
  */
-export function linkifyAndSanitizeHtml(dirtyHtml, options = linkifyMatrix.options) {
+export function linkifyAndSanitizeHtml(dirtyHtml: string, options = linkifyMatrix.options) {
     return sanitizeHtml(linkifyString(dirtyHtml, options), sanitizeHtmlParams);
 }
 
@@ -504,7 +518,7 @@ export function linkifyAndSanitizeHtml(dirtyHtml, options = linkifyMatrix.option
  * @param {Node} node
  * @returns {bool}
  */
-export function checkBlockNode(node) {
+export function checkBlockNode(node: Node) {
     switch (node.nodeName) {
         case "H1":
         case "H2":
diff --git a/src/accessibility/RovingTabIndex.js b/src/accessibility/RovingTabIndex.tsx
similarity index 75%
rename from src/accessibility/RovingTabIndex.js
rename to src/accessibility/RovingTabIndex.tsx
index b481f08fe2..388d67d9f3 100644
--- a/src/accessibility/RovingTabIndex.js
+++ b/src/accessibility/RovingTabIndex.tsx
@@ -22,9 +22,13 @@ import React, {
     useMemo,
     useRef,
     useReducer,
+    Reducer,
+    RefObject,
+    Dispatch,
 } from "react";
-import PropTypes from "prop-types";
+
 import {Key} from "../Keyboard";
+import AccessibleButton from "../components/views/elements/AccessibleButton";
 
 /**
  * Module to simplify implementing the Roving TabIndex accessibility technique
@@ -41,7 +45,19 @@ import {Key} from "../Keyboard";
 
 const DOCUMENT_POSITION_PRECEDING = 2;
 
-const RovingTabIndexContext = createContext({
+type Ref = RefObject<HTMLElement>;
+
+interface IState {
+    activeRef: Ref;
+    refs: Ref[];
+}
+
+interface IContext {
+    state: IState;
+    dispatch: Dispatch<IAction>;
+}
+
+const RovingTabIndexContext = createContext<IContext>({
     state: {
         activeRef: null,
         refs: [], // list of refs in DOM order
@@ -50,16 +66,22 @@ const RovingTabIndexContext = createContext({
 });
 RovingTabIndexContext.displayName = "RovingTabIndexContext";
 
-// TODO use a TypeScript type here
-const types = {
-    REGISTER: "REGISTER",
-    UNREGISTER: "UNREGISTER",
-    SET_FOCUS: "SET_FOCUS",
-};
+enum Type {
+    Register = "REGISTER",
+    Unregister = "UNREGISTER",
+    SetFocus = "SET_FOCUS",
+}
 
-const reducer = (state, action) => {
+interface IAction {
+    type: Type;
+    payload: {
+        ref: Ref;
+    };
+}
+
+const reducer = (state: IState, action: IAction) => {
     switch (action.type) {
-        case types.REGISTER: {
+        case Type.Register: {
             if (state.refs.length === 0) {
                 // Our list of refs was empty, set activeRef to this first item
                 return {
@@ -92,7 +114,7 @@ const reducer = (state, action) => {
                 ],
             };
         }
-        case types.UNREGISTER: {
+        case Type.Unregister: {
             // filter out the ref which we are removing
             const refs = state.refs.filter(r => r !== action.payload.ref);
 
@@ -117,7 +139,7 @@ const reducer = (state, action) => {
                 refs,
             };
         }
-        case types.SET_FOCUS: {
+        case Type.SetFocus: {
             // update active ref
             return {
                 ...state,
@@ -129,13 +151,21 @@ const reducer = (state, action) => {
     }
 };
 
-export const RovingTabIndexProvider = ({children, handleHomeEnd, onKeyDown}) => {
-    const [state, dispatch] = useReducer(reducer, {
+interface IProps {
+    handleHomeEnd?: boolean;
+    children(renderProps: {
+        onKeyDownHandler(ev: React.KeyboardEvent);
+    });
+    onKeyDown?(ev: React.KeyboardEvent);
+}
+
+export const RovingTabIndexProvider: React.FC<IProps> = ({children, handleHomeEnd, onKeyDown}) => {
+    const [state, dispatch] = useReducer<Reducer<IState, IAction>>(reducer, {
         activeRef: null,
         refs: [],
     });
 
-    const context = useMemo(() => ({state, dispatch}), [state]);
+    const context = useMemo<IContext>(() => ({state, dispatch}), [state]);
 
     const onKeyDownHandler = useCallback((ev) => {
         let handled = false;
@@ -171,19 +201,17 @@ export const RovingTabIndexProvider = ({children, handleHomeEnd, onKeyDown}) =>
         { children({onKeyDownHandler}) }
     </RovingTabIndexContext.Provider>;
 };
-RovingTabIndexProvider.propTypes = {
-    handleHomeEnd: PropTypes.bool,
-    onKeyDown: PropTypes.func,
-};
+
+type FocusHandler = () => void;
 
 // Hook to register a roving tab index
 // inputRef parameter specifies the ref to use
 // onFocus should be called when the index gained focus in any manner
 // isActive should be used to set tabIndex in a manner such as `tabIndex={isActive ? 0 : -1}`
 // ref should be passed to a DOM node which will be used for DOM compareDocumentPosition
-export const useRovingTabIndex = (inputRef) => {
+export const useRovingTabIndex = (inputRef: Ref): [FocusHandler, boolean, Ref] => {
     const context = useContext(RovingTabIndexContext);
-    let ref = useRef(null);
+    let ref = useRef<HTMLElement>(null);
 
     if (inputRef) {
         // if we are given a ref, use it instead of ours
@@ -193,13 +221,13 @@ export const useRovingTabIndex = (inputRef) => {
     // setup (after refs)
     useLayoutEffect(() => {
         context.dispatch({
-            type: types.REGISTER,
+            type: Type.Register,
             payload: {ref},
         });
         // teardown
         return () => {
             context.dispatch({
-                type: types.UNREGISTER,
+                type: Type.Unregister,
                 payload: {ref},
             });
         };
@@ -207,7 +235,7 @@ export const useRovingTabIndex = (inputRef) => {
 
     const onFocus = useCallback(() => {
         context.dispatch({
-            type: types.SET_FOCUS,
+            type: Type.SetFocus,
             payload: {ref},
         });
     }, [ref, context]);
@@ -216,9 +244,28 @@ export const useRovingTabIndex = (inputRef) => {
     return [onFocus, isActive, ref];
 };
 
+interface IRovingTabIndexWrapperProps {
+    inputRef?: Ref;
+    children(renderProps: {
+        onFocus: FocusHandler;
+        isActive: boolean;
+        ref: Ref;
+    });
+}
+
 // Wrapper to allow use of useRovingTabIndex outside of React Functional Components.
-export const RovingTabIndexWrapper = ({children, inputRef}) => {
+export const RovingTabIndexWrapper: React.FC<IRovingTabIndexWrapperProps> = ({children, inputRef}) => {
     const [onFocus, isActive, ref] = useRovingTabIndex(inputRef);
     return children({onFocus, isActive, ref});
 };
 
+interface IRovingAccessibleButtonProps extends React.ComponentProps<typeof AccessibleButton> {
+    inputRef?: Ref;
+}
+
+// Wrapper to allow use of useRovingTabIndex for simple AccessibleButtons outside of React Functional Components.
+export const RovingAccessibleButton: React.FC<IRovingAccessibleButtonProps> = ({inputRef, ...props}) => {
+    const [onFocus, isActive, ref] = useRovingTabIndex(inputRef);
+    return <AccessibleButton {...props} onFocus={onFocus} inputRef={ref} tabIndex={isActive ? 0 : -1} />;
+};
+
diff --git a/src/accessibility/context_menu/ContextMenuButton.tsx b/src/accessibility/context_menu/ContextMenuButton.tsx
new file mode 100644
index 0000000000..c358155e10
--- /dev/null
+++ b/src/accessibility/context_menu/ContextMenuButton.tsx
@@ -0,0 +1,51 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2018 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from "react";
+
+import AccessibleButton, {IProps as IAccessibleButtonProps} from "../../components/views/elements/AccessibleButton";
+
+interface IProps extends IAccessibleButtonProps {
+    label?: string;
+    // whether or not the context menu is currently open
+    isExpanded: boolean;
+}
+
+// Semantic component for representing the AccessibleButton which launches a <ContextMenu />
+export const ContextMenuButton: React.FC<IProps> = ({
+    label,
+    isExpanded,
+    children,
+    onClick,
+    onContextMenu,
+    ...props
+}) => {
+    return (
+        <AccessibleButton
+            {...props}
+            onClick={onClick}
+            onContextMenu={onContextMenu || onClick}
+            title={label}
+            aria-label={label}
+            aria-haspopup={true}
+            aria-expanded={isExpanded}
+        >
+            { children }
+        </AccessibleButton>
+    );
+};
diff --git a/src/accessibility/context_menu/MenuGroup.tsx b/src/accessibility/context_menu/MenuGroup.tsx
new file mode 100644
index 0000000000..9334e17a18
--- /dev/null
+++ b/src/accessibility/context_menu/MenuGroup.tsx
@@ -0,0 +1,30 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2018 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from "react";
+
+interface IProps extends React.HTMLAttributes<HTMLDivElement> {
+    label: string;
+}
+
+// Semantic component for representing a role=group for grouping menu radios/checkboxes
+export const MenuGroup: React.FC<IProps> = ({children, label, ...props}) => {
+    return <div {...props} role="group" aria-label={label}>
+        { children }
+    </div>;
+};
diff --git a/src/accessibility/context_menu/MenuItem.tsx b/src/accessibility/context_menu/MenuItem.tsx
new file mode 100644
index 0000000000..64233e51ad
--- /dev/null
+++ b/src/accessibility/context_menu/MenuItem.tsx
@@ -0,0 +1,35 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2018 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from "react";
+
+import AccessibleButton from "../../components/views/elements/AccessibleButton";
+
+interface IProps extends React.ComponentProps<typeof AccessibleButton> {
+    label?: string;
+}
+
+// Semantic component for representing a role=menuitem
+export const MenuItem: React.FC<IProps> = ({children, label, ...props}) => {
+    return (
+        <AccessibleButton {...props} role="menuitem" tabIndex={-1} aria-label={label}>
+            { children }
+        </AccessibleButton>
+    );
+};
+
diff --git a/src/accessibility/context_menu/MenuItemCheckbox.tsx b/src/accessibility/context_menu/MenuItemCheckbox.tsx
new file mode 100644
index 0000000000..5eb8cc4819
--- /dev/null
+++ b/src/accessibility/context_menu/MenuItemCheckbox.tsx
@@ -0,0 +1,43 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2018 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from "react";
+
+import AccessibleButton from "../../components/views/elements/AccessibleButton";
+
+interface IProps extends React.ComponentProps<typeof AccessibleButton> {
+    label?: string;
+    active: boolean;
+}
+
+// Semantic component for representing a role=menuitemcheckbox
+export const MenuItemCheckbox: React.FC<IProps> = ({children, label, active, disabled, ...props}) => {
+    return (
+        <AccessibleButton
+            {...props}
+            role="menuitemcheckbox"
+            aria-checked={active}
+            aria-disabled={disabled}
+            disabled={disabled}
+            tabIndex={-1}
+            aria-label={label}
+        >
+            { children }
+        </AccessibleButton>
+    );
+};
diff --git a/src/accessibility/context_menu/MenuItemRadio.tsx b/src/accessibility/context_menu/MenuItemRadio.tsx
new file mode 100644
index 0000000000..472f13ff14
--- /dev/null
+++ b/src/accessibility/context_menu/MenuItemRadio.tsx
@@ -0,0 +1,43 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2018 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from "react";
+
+import AccessibleButton from "../../components/views/elements/AccessibleButton";
+
+interface IProps extends React.ComponentProps<typeof AccessibleButton> {
+    label?: string;
+    active: boolean;
+}
+
+// Semantic component for representing a role=menuitemradio
+export const MenuItemRadio: React.FC<IProps> = ({children, label, active, disabled, ...props}) => {
+    return (
+        <AccessibleButton
+            {...props}
+            role="menuitemradio"
+            aria-checked={active}
+            aria-disabled={disabled}
+            disabled={disabled}
+            tabIndex={-1}
+            aria-label={label}
+        >
+            { children }
+        </AccessibleButton>
+    );
+};
diff --git a/src/accessibility/context_menu/StyledMenuItemCheckbox.tsx b/src/accessibility/context_menu/StyledMenuItemCheckbox.tsx
new file mode 100644
index 0000000000..d373f892c9
--- /dev/null
+++ b/src/accessibility/context_menu/StyledMenuItemCheckbox.tsx
@@ -0,0 +1,64 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2018 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from "react";
+
+import {Key} from "../../Keyboard";
+import StyledCheckbox from "../../components/views/elements/StyledCheckbox";
+
+interface IProps extends React.ComponentProps<typeof StyledCheckbox> {
+    label?: string;
+    onChange(); // we handle keyup/down ourselves so lose the ChangeEvent
+    onClose(): void; // gets called after onChange on Key.ENTER
+}
+
+// Semantic component for representing a styled role=menuitemcheckbox
+export const StyledMenuItemCheckbox: React.FC<IProps> = ({children, label, onChange, onClose, ...props}) => {
+    const onKeyDown = (e: React.KeyboardEvent) => {
+        if (e.key === Key.ENTER || e.key === Key.SPACE) {
+            e.stopPropagation();
+            e.preventDefault();
+            onChange();
+            // Implements https://www.w3.org/TR/wai-aria-practices/#keyboard-interaction-12
+            if (e.key === Key.ENTER) {
+                onClose();
+            }
+        }
+    };
+    const onKeyUp = (e: React.KeyboardEvent) => {
+        // prevent the input default handler as we handle it on keydown to match
+        // https://www.w3.org/TR/wai-aria-practices/examples/menubar/menubar-2/menubar-2.html
+        if (e.key === Key.SPACE || e.key === Key.ENTER) {
+            e.stopPropagation();
+            e.preventDefault();
+        }
+    };
+    return (
+        <StyledCheckbox
+            {...props}
+            role="menuitemcheckbox"
+            tabIndex={-1}
+            aria-label={label}
+            onChange={onChange}
+            onKeyDown={onKeyDown}
+            onKeyUp={onKeyUp}
+        >
+            { children }
+        </StyledCheckbox>
+    );
+};
diff --git a/src/accessibility/context_menu/StyledMenuItemRadio.tsx b/src/accessibility/context_menu/StyledMenuItemRadio.tsx
new file mode 100644
index 0000000000..5e5aa90a38
--- /dev/null
+++ b/src/accessibility/context_menu/StyledMenuItemRadio.tsx
@@ -0,0 +1,64 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2018 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from "react";
+
+import {Key} from "../../Keyboard";
+import StyledRadioButton from "../../components/views/elements/StyledRadioButton";
+
+interface IProps extends React.ComponentProps<typeof StyledRadioButton> {
+    label?: string;
+    onChange(); // we handle keyup/down ourselves so lose the ChangeEvent
+    onClose(): void; // gets called after onChange on Key.ENTER
+}
+
+// Semantic component for representing a styled role=menuitemradio
+export const StyledMenuItemRadio: React.FC<IProps> = ({children, label, onChange, onClose, ...props}) => {
+    const onKeyDown = (e: React.KeyboardEvent) => {
+        if (e.key === Key.ENTER || e.key === Key.SPACE) {
+            e.stopPropagation();
+            e.preventDefault();
+            onChange();
+            // Implements https://www.w3.org/TR/wai-aria-practices/#keyboard-interaction-12
+            if (e.key === Key.ENTER) {
+                onClose();
+            }
+        }
+    };
+    const onKeyUp = (e: React.KeyboardEvent) => {
+        // prevent the input default handler as we handle it on keydown to match
+        // https://www.w3.org/TR/wai-aria-practices/examples/menubar/menubar-2/menubar-2.html
+        if (e.key === Key.SPACE || e.key === Key.ENTER) {
+            e.stopPropagation();
+            e.preventDefault();
+        }
+    };
+    return (
+        <StyledRadioButton
+            {...props}
+            role="menuitemradio"
+            tabIndex={-1}
+            aria-label={label}
+            onChange={onChange}
+            onKeyDown={onKeyDown}
+            onKeyUp={onKeyUp}
+        >
+            { children }
+        </StyledRadioButton>
+    );
+};
diff --git a/src/components/structures/ContextMenu.js b/src/components/structures/ContextMenu.tsx
similarity index 53%
rename from src/components/structures/ContextMenu.js
rename to src/components/structures/ContextMenu.tsx
index bda194ddd0..cb1349da4b 100644
--- a/src/components/structures/ContextMenu.js
+++ b/src/components/structures/ContextMenu.tsx
@@ -16,15 +16,12 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import React, {useRef, useState} from 'react';
-import ReactDOM from 'react-dom';
-import PropTypes from 'prop-types';
-import classNames from 'classnames';
+import React, {CSSProperties, useRef, useState} from "react";
+import ReactDOM from "react-dom";
+import classNames from "classnames";
+
 import {Key} from "../../Keyboard";
-import * as sdk from "../../index";
-import AccessibleButton from "../views/elements/AccessibleButton";
-import StyledCheckbox from "../views/elements/StyledCheckbox";
-import StyledRadioButton from "../views/elements/StyledRadioButton";
+import {Writeable} from "../../@types/common";
 
 // Shamelessly ripped off Modal.js.  There's probably a better way
 // of doing reusable widgets like dialog boxes & menus where we go and
@@ -32,8 +29,8 @@ import StyledRadioButton from "../views/elements/StyledRadioButton";
 
 const ContextualMenuContainerId = "mx_ContextualMenu_Container";
 
-function getOrCreateContainer() {
-    let container = document.getElementById(ContextualMenuContainerId);
+function getOrCreateContainer(): HTMLDivElement {
+    let container = document.getElementById(ContextualMenuContainerId) as HTMLDivElement;
 
     if (!container) {
         container = document.createElement("div");
@@ -45,50 +42,70 @@ function getOrCreateContainer() {
 }
 
 const ARIA_MENU_ITEM_ROLES = new Set(["menuitem", "menuitemcheckbox", "menuitemradio"]);
+
+interface IPosition {
+    top?: number;
+    bottom?: number;
+    left?: number;
+    right?: number;
+}
+
+export enum ChevronFace {
+    Top = "top",
+    Bottom = "bottom",
+    Left = "left",
+    Right = "right",
+    None = "none",
+}
+
+interface IProps extends IPosition {
+    menuWidth?: number;
+    menuHeight?: number;
+
+    chevronOffset?: number;
+    chevronFace?: ChevronFace;
+
+    menuPaddingTop?: number;
+    menuPaddingBottom?: number;
+    menuPaddingLeft?: number;
+    menuPaddingRight?: number;
+
+    zIndex?: number;
+
+    // If true, insert an invisible screen-sized element behind the menu that when clicked will close it.
+    hasBackground?: boolean;
+    // whether this context menu should be focus managed. If false it must handle itself
+    managed?: boolean;
+
+    // Function to be called on menu close
+    onFinished();
+    // on resize callback
+    windowResize?();
+}
+
+interface IState {
+    contextMenuElem: HTMLDivElement;
+}
+
 // Generic ContextMenu Portal wrapper
 // all options inside the menu should be of role=menuitem/menuitemcheckbox/menuitemradiobutton and have tabIndex={-1}
 // this will allow the ContextMenu to manage its own focus using arrow keys as per the ARIA guidelines.
-export class ContextMenu extends React.Component {
-    static propTypes = {
-        top: PropTypes.number,
-        bottom: PropTypes.number,
-        left: PropTypes.number,
-        right: PropTypes.number,
-        menuWidth: PropTypes.number,
-        menuHeight: PropTypes.number,
-        chevronOffset: PropTypes.number,
-        chevronFace: PropTypes.string, // top, bottom, left, right or none
-        // Function to be called on menu close
-        onFinished: PropTypes.func.isRequired,
-        menuPaddingTop: PropTypes.number,
-        menuPaddingRight: PropTypes.number,
-        menuPaddingBottom: PropTypes.number,
-        menuPaddingLeft: PropTypes.number,
-        zIndex: PropTypes.number,
-
-        // If true, insert an invisible screen-sized element behind the
-        // menu that when clicked will close it.
-        hasBackground: PropTypes.bool,
-
-        // on resize callback
-        windowResize: PropTypes.func,
-
-        managed: PropTypes.bool, // whether this context menu should be focus managed. If false it must handle itself
-    };
+export class ContextMenu extends React.PureComponent<IProps, IState> {
+    private initialFocus: HTMLElement;
 
     static defaultProps = {
         hasBackground: true,
         managed: true,
     };
 
-    constructor() {
-        super();
+    constructor(props, context) {
+        super(props, context);
         this.state = {
             contextMenuElem: null,
         };
 
         // persist what had focus when we got initialized so we can return it after
-        this.initialFocus = document.activeElement;
+        this.initialFocus = document.activeElement as HTMLElement;
     }
 
     componentWillUnmount() {
@@ -96,7 +113,7 @@ export class ContextMenu extends React.Component {
         this.initialFocus.focus();
     }
 
-    collectContextMenuRect = (element) => {
+    private collectContextMenuRect = (element) => {
         // We don't need to clean up when unmounting, so ignore
         if (!element) return;
 
@@ -113,7 +130,7 @@ export class ContextMenu extends React.Component {
         });
     };
 
-    onContextMenu = (e) => {
+    private onContextMenu = (e) => {
         if (this.props.onFinished) {
             this.props.onFinished();
 
@@ -136,20 +153,20 @@ export class ContextMenu extends React.Component {
         }
     };
 
-    onContextMenuPreventBubbling = (e) => {
+    private onContextMenuPreventBubbling = (e) => {
         // stop propagation so that any context menu handlers don't leak out of this context menu
         // but do not inhibit the default browser menu
         e.stopPropagation();
     };
 
     // Prevent clicks on the background from going through to the component which opened the menu.
-    _onFinished = (ev: InputEvent) => {
+    private onFinished = (ev: React.MouseEvent) => {
         ev.stopPropagation();
         ev.preventDefault();
         if (this.props.onFinished) this.props.onFinished();
     };
 
-    _onMoveFocus = (element, up) => {
+    private onMoveFocus = (element: Element, up: boolean) => {
         let descending = false; // are we currently descending or ascending through the DOM tree?
 
         do {
@@ -183,25 +200,25 @@ export class ContextMenu extends React.Component {
         } while (element && !ARIA_MENU_ITEM_ROLES.has(element.getAttribute("role")));
 
         if (element) {
-            element.focus();
+            (element as HTMLElement).focus();
         }
     };
 
-    _onMoveFocusHomeEnd = (element, up) => {
+    private onMoveFocusHomeEnd = (element: Element, up: boolean) => {
         let results = element.querySelectorAll('[role^="menuitem"]');
         if (!results) {
             results = element.querySelectorAll('[tab-index]');
         }
         if (results && results.length) {
             if (up) {
-                results[0].focus();
+                (results[0] as HTMLElement).focus();
             } else {
-                results[results.length - 1].focus();
+                (results[results.length - 1] as HTMLElement).focus();
             }
         }
     };
 
-    _onKeyDown = (ev) => {
+    private onKeyDown = (ev: React.KeyboardEvent) => {
         if (!this.props.managed) {
             if (ev.key === Key.ESCAPE) {
                 this.props.onFinished();
@@ -219,16 +236,16 @@ export class ContextMenu extends React.Component {
                 this.props.onFinished();
                 break;
             case Key.ARROW_UP:
-                this._onMoveFocus(ev.target, true);
+                this.onMoveFocus(ev.target as Element, true);
                 break;
             case Key.ARROW_DOWN:
-                this._onMoveFocus(ev.target, false);
+                this.onMoveFocus(ev.target as Element, false);
                 break;
             case Key.HOME:
-                this._onMoveFocusHomeEnd(this.state.contextMenuElem, true);
+                this.onMoveFocusHomeEnd(this.state.contextMenuElem, true);
                 break;
             case Key.END:
-                this._onMoveFocusHomeEnd(this.state.contextMenuElem, false);
+                this.onMoveFocusHomeEnd(this.state.contextMenuElem, false);
                 break;
             default:
                 handled = false;
@@ -241,9 +258,8 @@ export class ContextMenu extends React.Component {
         }
     };
 
-    renderMenu(hasBackground=this.props.hasBackground) {
-        const position = {};
-        let chevronFace = null;
+    protected renderMenu(hasBackground = this.props.hasBackground) {
+        const position: Partial<Writeable<DOMRect>> = {};
         const props = this.props;
 
         if (props.top) {
@@ -252,23 +268,24 @@ export class ContextMenu extends React.Component {
             position.bottom = props.bottom;
         }
 
+        let chevronFace: ChevronFace;
         if (props.left) {
             position.left = props.left;
-            chevronFace = 'left';
+            chevronFace = ChevronFace.Left;
         } else {
             position.right = props.right;
-            chevronFace = 'right';
+            chevronFace = ChevronFace.Right;
         }
 
         const contextMenuRect = this.state.contextMenuElem ? this.state.contextMenuElem.getBoundingClientRect() : null;
 
-        const chevronOffset = {};
+        const chevronOffset: CSSProperties = {};
         if (props.chevronFace) {
             chevronFace = props.chevronFace;
         }
-        const hasChevron = chevronFace && chevronFace !== "none";
+        const hasChevron = chevronFace && chevronFace !== ChevronFace.None;
 
-        if (chevronFace === 'top' || chevronFace === 'bottom') {
+        if (chevronFace === ChevronFace.Top || chevronFace === ChevronFace.Bottom) {
             chevronOffset.left = props.chevronOffset;
         } else if (position.top !== undefined) {
             const target = position.top;
@@ -298,13 +315,13 @@ export class ContextMenu extends React.Component {
             'mx_ContextualMenu_right': !hasChevron && position.right,
             'mx_ContextualMenu_top': !hasChevron && position.top,
             'mx_ContextualMenu_bottom': !hasChevron && position.bottom,
-            'mx_ContextualMenu_withChevron_left': chevronFace === 'left',
-            'mx_ContextualMenu_withChevron_right': chevronFace === 'right',
-            'mx_ContextualMenu_withChevron_top': chevronFace === 'top',
-            'mx_ContextualMenu_withChevron_bottom': chevronFace === 'bottom',
+            'mx_ContextualMenu_withChevron_left': chevronFace === ChevronFace.Left,
+            'mx_ContextualMenu_withChevron_right': chevronFace === ChevronFace.Right,
+            'mx_ContextualMenu_withChevron_top': chevronFace === ChevronFace.Top,
+            'mx_ContextualMenu_withChevron_bottom': chevronFace === ChevronFace.Bottom,
         });
 
-        const menuStyle = {};
+        const menuStyle: CSSProperties = {};
         if (props.menuWidth) {
             menuStyle.width = props.menuWidth;
         }
@@ -335,13 +352,28 @@ export class ContextMenu extends React.Component {
         let background;
         if (hasBackground) {
             background = (
-                <div className="mx_ContextualMenu_background" style={wrapperStyle} onClick={this._onFinished} onContextMenu={this.onContextMenu} />
+                <div
+                    className="mx_ContextualMenu_background"
+                    style={wrapperStyle}
+                    onClick={this.onFinished}
+                    onContextMenu={this.onContextMenu}
+                />
             );
         }
 
         return (
-            <div className="mx_ContextualMenu_wrapper" style={{...position, ...wrapperStyle}} onKeyDown={this._onKeyDown} onContextMenu={this.onContextMenuPreventBubbling}>
-                <div className={menuClasses} style={menuStyle} ref={this.collectContextMenuRect} role={this.props.managed ? "menu" : undefined}>
+            <div
+                className="mx_ContextualMenu_wrapper"
+                style={{...position, ...wrapperStyle}}
+                onKeyDown={this.onKeyDown}
+                onContextMenu={this.onContextMenuPreventBubbling}
+            >
+                <div
+                    className={menuClasses}
+                    style={menuStyle}
+                    ref={this.collectContextMenuRect}
+                    role={this.props.managed ? "menu" : undefined}
+                >
                     { chevron }
                     { props.children }
                 </div>
@@ -350,195 +382,13 @@ export class ContextMenu extends React.Component {
         );
     }
 
-    render() {
+    render(): React.ReactChild {
         return ReactDOM.createPortal(this.renderMenu(), getOrCreateContainer());
     }
 }
 
-// Semantic component for representing the AccessibleButton which launches a <ContextMenu />
-export const ContextMenuButton = ({ label, isExpanded, children, onClick, onContextMenu, ...props }) => {
-    const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
-    return (
-        <AccessibleButton
-            {...props}
-            onClick={onClick}
-            onContextMenu={onContextMenu || onClick}
-            title={label}
-            aria-label={label}
-            aria-haspopup={true}
-            aria-expanded={isExpanded}
-        >
-            { children }
-        </AccessibleButton>
-    );
-};
-ContextMenuButton.propTypes = {
-    ...AccessibleButton.propTypes,
-    label: PropTypes.string,
-    isExpanded: PropTypes.bool.isRequired, // whether or not the context menu is currently open
-};
-
-// Semantic component for representing a role=menuitem
-export const MenuItem = ({children, label, ...props}) => {
-    const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
-    return (
-        <AccessibleButton {...props} role="menuitem" tabIndex={-1} aria-label={label}>
-            { children }
-        </AccessibleButton>
-    );
-};
-MenuItem.propTypes = {
-    ...AccessibleButton.propTypes,
-    label: PropTypes.string, // optional
-    className: PropTypes.string, // optional
-    onClick: PropTypes.func.isRequired,
-};
-
-// Semantic component for representing a role=group for grouping menu radios/checkboxes
-export const MenuGroup = ({children, label, ...props}) => {
-    return <div {...props} role="group" aria-label={label}>
-        { children }
-    </div>;
-};
-MenuGroup.propTypes = {
-    label: PropTypes.string.isRequired,
-    className: PropTypes.string, // optional
-};
-
-// Semantic component for representing a role=menuitemcheckbox
-export const MenuItemCheckbox = ({children, label, active=false, disabled=false, ...props}) => {
-    const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
-    return (
-        <AccessibleButton {...props} role="menuitemcheckbox" aria-checked={active} aria-disabled={disabled} tabIndex={-1} aria-label={label}>
-            { children }
-        </AccessibleButton>
-    );
-};
-MenuItemCheckbox.propTypes = {
-    ...AccessibleButton.propTypes,
-    label: PropTypes.string, // optional
-    active: PropTypes.bool.isRequired,
-    disabled: PropTypes.bool, // optional
-    className: PropTypes.string, // optional
-    onClick: PropTypes.func.isRequired,
-};
-
-// Semantic component for representing a styled role=menuitemcheckbox
-export const StyledMenuItemCheckbox = ({children, label, onChange, onClose, checked, disabled=false, ...props}) => {
-    const onKeyDown = (e) => {
-        if (e.key === Key.ENTER || e.key === Key.SPACE) {
-            e.stopPropagation();
-            e.preventDefault();
-            onChange();
-            // Implements https://www.w3.org/TR/wai-aria-practices/#keyboard-interaction-12
-            if (e.key === Key.ENTER) {
-                onClose();
-            }
-        }
-    };
-    const onKeyUp = (e) => {
-        // prevent the input default handler as we handle it on keydown to match
-        // https://www.w3.org/TR/wai-aria-practices/examples/menubar/menubar-2/menubar-2.html
-        if (e.key === Key.SPACE || e.key === Key.ENTER) {
-            e.stopPropagation();
-            e.preventDefault();
-        }
-    };
-    return (
-        <StyledCheckbox
-            {...props}
-            role="menuitemcheckbox"
-            aria-checked={checked}
-            checked={checked}
-            aria-disabled={disabled}
-            tabIndex={-1}
-            aria-label={label}
-            onChange={onChange}
-            onKeyDown={onKeyDown}
-            onKeyUp={onKeyUp}
-        >
-            { children }
-        </StyledCheckbox>
-    );
-};
-StyledMenuItemCheckbox.propTypes = {
-    ...StyledCheckbox.propTypes,
-    label: PropTypes.string, // optional
-    checked: PropTypes.bool.isRequired,
-    disabled: PropTypes.bool, // optional
-    className: PropTypes.string, // optional
-    onChange: PropTypes.func.isRequired,
-    onClose: PropTypes.func.isRequired, // gets called after onChange on Key.ENTER
-};
-
-// Semantic component for representing a role=menuitemradio
-export const MenuItemRadio = ({children, label, active=false, disabled=false, ...props}) => {
-    const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
-    return (
-        <AccessibleButton {...props} role="menuitemradio" aria-checked={active} aria-disabled={disabled} tabIndex={-1} aria-label={label}>
-            { children }
-        </AccessibleButton>
-    );
-};
-MenuItemRadio.propTypes = {
-    ...AccessibleButton.propTypes,
-    label: PropTypes.string, // optional
-    active: PropTypes.bool.isRequired,
-    disabled: PropTypes.bool, // optional
-    className: PropTypes.string, // optional
-    onClick: PropTypes.func.isRequired,
-};
-
-// Semantic component for representing a styled role=menuitemradio
-export const StyledMenuItemRadio = ({children, label, onChange, onClose, checked=false, disabled=false, ...props}) => {
-    const onKeyDown = (e) => {
-        if (e.key === Key.ENTER || e.key === Key.SPACE) {
-            e.stopPropagation();
-            e.preventDefault();
-            onChange();
-            // Implements https://www.w3.org/TR/wai-aria-practices/#keyboard-interaction-12
-            if (e.key === Key.ENTER) {
-                onClose();
-            }
-        }
-    };
-    const onKeyUp = (e) => {
-        // prevent the input default handler as we handle it on keydown to match
-        // https://www.w3.org/TR/wai-aria-practices/examples/menubar/menubar-2/menubar-2.html
-        if (e.key === Key.SPACE || e.key === Key.ENTER) {
-            e.stopPropagation();
-            e.preventDefault();
-        }
-    };
-    return (
-        <StyledRadioButton
-            {...props}
-            role="menuitemradio"
-            aria-checked={checked}
-            checked={checked}
-            aria-disabled={disabled}
-            tabIndex={-1}
-            aria-label={label}
-            onChange={onChange}
-            onKeyDown={onKeyDown}
-            onKeyUp={onKeyUp}
-        >
-            { children }
-        </StyledRadioButton>
-    );
-};
-StyledMenuItemRadio.propTypes = {
-    ...StyledMenuItemRadio.propTypes,
-    label: PropTypes.string, // optional
-    checked: PropTypes.bool.isRequired,
-    disabled: PropTypes.bool, // optional
-    className: PropTypes.string, // optional
-    onChange: PropTypes.func.isRequired,
-    onClose: PropTypes.func.isRequired, // gets called after onChange on Key.ENTER
-};
-
 // Placement method for <ContextMenu /> to position context menu to right of elementRect with chevronOffset
-export const toRightOf = (elementRect, chevronOffset=12) => {
+export const toRightOf = (elementRect: DOMRect, chevronOffset = 12) => {
     const left = elementRect.right + window.pageXOffset + 3;
     let top = elementRect.top + (elementRect.height / 2) + window.pageYOffset;
     top -= chevronOffset + 8; // where 8 is half the height of the chevron
@@ -546,8 +396,8 @@ export const toRightOf = (elementRect, chevronOffset=12) => {
 };
 
 // Placement method for <ContextMenu /> to position context menu right-aligned and flowing to the left of elementRect
-export const aboveLeftOf = (elementRect, chevronFace="none") => {
-    const menuOptions = { chevronFace };
+export const aboveLeftOf = (elementRect: DOMRect, chevronFace = ChevronFace.None) => {
+    const menuOptions: IPosition & { chevronFace: ChevronFace } = { chevronFace };
 
     const buttonRight = elementRect.right + window.pageXOffset;
     const buttonBottom = elementRect.bottom + window.pageYOffset;
@@ -605,3 +455,12 @@ export function createMenu(ElementClass, props) {
 
     return {close: onFinished};
 }
+
+// re-export the semantic helper components for simplicity
+export {ContextMenuButton} from "../../accessibility/context_menu/ContextMenuButton";
+export {MenuGroup} from "../../accessibility/context_menu/MenuGroup";
+export {MenuItem} from "../../accessibility/context_menu/MenuItem";
+export {MenuItemCheckbox} from "../../accessibility/context_menu/MenuItemCheckbox";
+export {MenuItemRadio} from "../../accessibility/context_menu/MenuItemRadio";
+export {StyledMenuItemCheckbox} from "../../accessibility/context_menu/StyledMenuItemCheckbox";
+export {StyledMenuItemRadio} from "../../accessibility/context_menu/StyledMenuItemRadio";
diff --git a/src/components/structures/LeftPanel2.tsx b/src/components/structures/LeftPanel2.tsx
index 4b954d7843..e92b0fa9ae 100644
--- a/src/components/structures/LeftPanel2.tsx
+++ b/src/components/structures/LeftPanel2.tsx
@@ -21,6 +21,7 @@ import classNames from "classnames";
 import dis from "../../dispatcher/dispatcher";
 import { _t } from "../../languageHandler";
 import RoomList2 from "../views/rooms/RoomList2";
+import { HEADER_HEIGHT } from "../views/rooms/RoomSublist2";
 import { Action } from "../../dispatcher/actions";
 import UserMenu from "./UserMenu";
 import RoomSearch from "./RoomSearch";
@@ -69,8 +70,7 @@ export default class LeftPanel2 extends React.Component<IProps, IState> {
     private listContainerRef: React.RefObject<HTMLDivElement> = createRef();
     private tagPanelWatcherRef: string;
     private focusedElement = null;
-
-    // TODO: a11y: https://github.com/vector-im/riot-web/issues/14180
+    private isDoingStickyHeaders = false;
 
     constructor(props: IProps) {
         super(props);
@@ -115,11 +115,27 @@ export default class LeftPanel2 extends React.Component<IProps, IState> {
     };
 
     private handleStickyHeaders(list: HTMLDivElement) {
+        // TODO: Evaluate if this has any performance benefit or detriment.
+        // See https://github.com/vector-im/riot-web/issues/14035
+
+        if (this.isDoingStickyHeaders) return;
+        this.isDoingStickyHeaders = true;
+        if (window.requestAnimationFrame) {
+            window.requestAnimationFrame(() => {
+                this.doStickyHeaders(list);
+                this.isDoingStickyHeaders = false;
+            });
+        } else {
+            this.doStickyHeaders(list);
+            this.isDoingStickyHeaders = false;
+        }
+    }
+
+    private doStickyHeaders(list: HTMLDivElement) {
         const rlRect = list.getBoundingClientRect();
         const bottom = rlRect.bottom;
         const top = rlRect.top;
         const sublists = list.querySelectorAll<HTMLDivElement>(".mx_RoomSublist2");
-        const headerHeight = 32; // Note: must match the CSS!
         const headerRightMargin = 24; // calculated from margins and widths to align with non-sticky tiles
 
         const headerStickyWidth = rlRect.width - headerRightMargin;
@@ -130,23 +146,27 @@ export default class LeftPanel2 extends React.Component<IProps, IState> {
             const slRect = sublist.getBoundingClientRect();
 
             const header = sublist.querySelector<HTMLDivElement>(".mx_RoomSublist2_stickable");
+            header.style.removeProperty("display"); // always clear display:none first
 
-            if (slRect.top + headerHeight > bottom && !gotBottom) {
+            if (slRect.top + HEADER_HEIGHT > bottom && !gotBottom) {
                 header.classList.add("mx_RoomSublist2_headerContainer_sticky");
                 header.classList.add("mx_RoomSublist2_headerContainer_stickyBottom");
                 header.style.width = `${headerStickyWidth}px`;
                 header.style.removeProperty("top");
                 gotBottom = true;
-            } else if ((slRect.top - (headerHeight / 3)) < top) {
+            } else if (((slRect.top - (HEADER_HEIGHT * 0.6) + HEADER_HEIGHT) < top) || sublist === sublists[0]) {
+                // the header should become sticky once it is 60% or less out of view at the top.
+                // We also add HEADER_HEIGHT because the sticky header is put above the scrollable area,
+                // into the padding of .mx_LeftPanel2_roomListWrapper,
+                // by subtracting HEADER_HEIGHT from the top below.
+                // We also always try to make the first sublist header sticky.
                 header.classList.add("mx_RoomSublist2_headerContainer_sticky");
                 header.classList.add("mx_RoomSublist2_headerContainer_stickyTop");
                 header.style.width = `${headerStickyWidth}px`;
-                header.style.top = `${rlRect.top}px`;
+                header.style.top = `${rlRect.top - HEADER_HEIGHT}px`;
                 if (lastTopHeader) {
                     lastTopHeader.style.display = "none";
                 }
-                // first unset it, if set in last iteration
-                header.style.removeProperty("display");
                 lastTopHeader = header;
             } else {
                 header.classList.remove("mx_RoomSublist2_headerContainer_sticky");
@@ -156,6 +176,26 @@ export default class LeftPanel2 extends React.Component<IProps, IState> {
                 header.style.removeProperty("top");
             }
         }
+
+        // add appropriate sticky classes to wrapper so it has
+        // the necessary top/bottom padding to put the sticky header in
+        const listWrapper = list.parentElement;
+        if (gotBottom) {
+            listWrapper.classList.add("stickyBottom");
+        } else {
+            listWrapper.classList.remove("stickyBottom");
+        }
+        if (lastTopHeader) {
+            listWrapper.classList.add("stickyTop");
+        } else {
+            listWrapper.classList.remove("stickyTop");
+        }
+
+        // ensure scroll doesn't go above the gap left by the header of
+        // the first sublist always being sticky if no other header is sticky
+        if (list.scrollTop < HEADER_HEIGHT) {
+            list.scrollTop = HEADER_HEIGHT;
+        }
     }
 
     // TODO: Improve header reliability: https://github.com/vector-im/riot-web/issues/14232
@@ -264,7 +304,6 @@ export default class LeftPanel2 extends React.Component<IProps, IState> {
                     onVerticalArrow={this.onKeyDown}
                 />
                 <AccessibleButton
-                    // TODO fix the accessibility of this: https://github.com/vector-im/riot-web/issues/14180
                     className="mx_LeftPanel2_exploreButton"
                     onClick={this.onExplore}
                     title={_t("Explore rooms")}
@@ -310,15 +349,17 @@ export default class LeftPanel2 extends React.Component<IProps, IState> {
                 <aside className="mx_LeftPanel2_roomListContainer">
                     {this.renderHeader()}
                     {this.renderSearchExplore()}
-                    <div
-                        className={roomListClasses}
-                        onScroll={this.onScroll}
-                        ref={this.listContainerRef}
-                        // Firefox sometimes makes this element focusable due to
-                        // overflow:scroll;, so force it out of tab order.
-                        tabIndex={-1}
-                    >
-                        {roomList}
+                    <div className="mx_LeftPanel2_roomListWrapper">
+                        <div
+                            className={roomListClasses}
+                            onScroll={this.onScroll}
+                            ref={this.listContainerRef}
+                            // Firefox sometimes makes this element focusable due to
+                            // overflow:scroll;, so force it out of tab order.
+                            tabIndex={-1}
+                        >
+                            {roomList}
+                        </div>
                     </div>
                 </aside>
             </div>
diff --git a/src/components/structures/RoomSearch.tsx b/src/components/structures/RoomSearch.tsx
index 15f3bd5b54..bb82ab8f63 100644
--- a/src/components/structures/RoomSearch.tsx
+++ b/src/components/structures/RoomSearch.tsx
@@ -81,6 +81,7 @@ export default class RoomSearch extends React.PureComponent<IProps, IState> {
 
     private openSearch = () => {
         defaultDispatcher.dispatch({action: "show_left_panel"});
+        defaultDispatcher.dispatch({action: "focus_room_filter"});
     };
 
     private onChange = () => {
diff --git a/src/components/structures/UserMenu.tsx b/src/components/structures/UserMenu.tsx
index 221ec07439..0cc312d653 100644
--- a/src/components/structures/UserMenu.tsx
+++ b/src/components/structures/UserMenu.tsx
@@ -14,14 +14,13 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import * as React from "react";
+import React, { createRef } from "react";
 import { MatrixClientPeg } from "../../MatrixClientPeg";
 import defaultDispatcher from "../../dispatcher/dispatcher";
 import { ActionPayload } from "../../dispatcher/payloads";
 import { Action } from "../../dispatcher/actions";
-import { createRef } from "react";
 import { _t } from "../../languageHandler";
-import {ContextMenu, ContextMenuButton, MenuItem} from "./ContextMenu";
+import { ChevronFace, ContextMenu, ContextMenuButton, MenuItem } from "./ContextMenu";
 import {USER_NOTIFICATIONS_TAB, USER_SECURITY_TAB} from "../views/dialogs/UserSettingsDialog";
 import { OpenToTabPayload } from "../../dispatcher/payloads/OpenToTabPayload";
 import RedesignFeedbackDialog from "../views/dialogs/RedesignFeedbackDialog";
@@ -122,7 +121,7 @@ export default class UserMenu extends React.Component<IProps, IState> {
         }
     };
 
-    private onOpenMenuClick = (ev: InputEvent) => {
+    private onOpenMenuClick = (ev: React.MouseEvent) => {
         ev.preventDefault();
         ev.stopPropagation();
         const target = ev.target as HTMLButtonElement;
@@ -235,7 +234,7 @@ export default class UserMenu extends React.Component<IProps, IState> {
 
         return (
             <ContextMenu
-                chevronFace="none"
+                chevronFace={ChevronFace.None}
                 // -20 to overlap the context menu by just over the width of the `...` icon and make it look connected
                 left={this.state.contextMenuPosition.width + this.state.contextMenuPosition.left - 20}
                 top={this.state.contextMenuPosition.top + this.state.contextMenuPosition.height}
diff --git a/src/components/views/elements/AccessibleButton.tsx b/src/components/views/elements/AccessibleButton.tsx
index 040147bb16..34481601f7 100644
--- a/src/components/views/elements/AccessibleButton.tsx
+++ b/src/components/views/elements/AccessibleButton.tsx
@@ -64,7 +64,6 @@ export default function AccessibleButton({
     className,
     ...restProps
 }: IProps) {
-
     const newProps: IAccessibleButtonProps = restProps;
     if (!disabled) {
         newProps.onClick = onClick;
diff --git a/src/components/views/elements/MemberEventListSummary.js b/src/components/views/elements/MemberEventListSummary.js
index fc79fc87d0..956b69ca7b 100644
--- a/src/components/views/elements/MemberEventListSummary.js
+++ b/src/components/views/elements/MemberEventListSummary.js
@@ -1,6 +1,6 @@
 /*
 Copyright 2016 OpenMarket Ltd
-Copyright 2019 The Matrix.org Foundation C.I.C.
+Copyright 2019, 2020 The Matrix.org Foundation C.I.C.
 Copyright 2019 Michael Telatynski <7t3chguy@gmail.com>
 
 Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,6 +23,7 @@ import { _t } from '../../../languageHandler';
 import { formatCommaSeparatedList } from '../../../utils/FormattingUtils';
 import * as sdk from "../../../index";
 import {MatrixEvent} from "matrix-js-sdk";
+import {isValid3pidInvite} from "../../../RoomInvite";
 
 export default createReactClass({
     displayName: 'MemberEventListSummary',
@@ -284,6 +285,9 @@ export default createReactClass({
     _getTransition: function(e) {
         if (e.mxEvent.getType() === 'm.room.third_party_invite') {
             // Handle 3pid invites the same as invites so they get bundled together
+            if (!isValid3pidInvite(e.mxEvent)) {
+                return 'invite_withdrawal';
+            }
             return 'invited';
         }
 
diff --git a/src/components/views/rooms/RoomSublist2.tsx b/src/components/views/rooms/RoomSublist2.tsx
index 18f8f4e2f6..732585d3ac 100644
--- a/src/components/views/rooms/RoomSublist2.tsx
+++ b/src/components/views/rooms/RoomSublist2.tsx
@@ -20,13 +20,13 @@ import * as React from "react";
 import { createRef } from "react";
 import { Room } from "matrix-js-sdk/src/models/room";
 import classNames from 'classnames';
-import { RovingTabIndexWrapper } from "../../../accessibility/RovingTabIndex";
+import {RovingAccessibleButton, RovingTabIndexWrapper} from "../../../accessibility/RovingTabIndex";
 import { _t } from "../../../languageHandler";
 import AccessibleButton from "../../views/elements/AccessibleButton";
 import RoomTile2 from "./RoomTile2";
-import { ResizableBox, ResizeCallbackData } from "react-resizable";
 import { ListLayout } from "../../../stores/room-list/ListLayout";
 import {
+    ChevronFace,
     ContextMenu,
     ContextMenuButton,
     StyledMenuItemCheckbox,
@@ -40,7 +40,11 @@ import NotificationBadge from "./NotificationBadge";
 import { ListNotificationState } from "../../../stores/notifications/ListNotificationState";
 import AccessibleTooltipButton from "../elements/AccessibleTooltipButton";
 import { Key } from "../../../Keyboard";
-import StyledCheckbox from "../elements/StyledCheckbox";
+import defaultDispatcher from "../../../dispatcher/dispatcher";
+import {ActionPayload} from "../../../dispatcher/payloads";
+import { Enable, Resizable } from "re-resizable";
+import { Direction } from "re-resizable/lib/resizer";
+import { polyfillTouchEvent } from "../../../@types/polyfill";
 
 // TODO: Remove banner on launch: https://github.com/vector-im/riot-web/issues/14231
 // TODO: Rename on launch: https://github.com/vector-im/riot-web/issues/14231
@@ -55,9 +59,13 @@ import StyledCheckbox from "../elements/StyledCheckbox";
 
 const SHOW_N_BUTTON_HEIGHT = 32; // As defined by CSS
 const RESIZE_HANDLE_HEIGHT = 4; // As defined by CSS
+export const HEADER_HEIGHT = 32; // As defined by CSS
 
 const MAX_PADDING_HEIGHT = SHOW_N_BUTTON_HEIGHT + RESIZE_HANDLE_HEIGHT;
 
+// HACK: We really shouldn't have to do this.
+polyfillTouchEvent();
+
 interface IProps {
     forRooms: boolean;
     rooms?: Room[];
@@ -89,6 +97,7 @@ interface IState {
 export default class RoomSublist2 extends React.Component<IProps, IState> {
     private headerButton = createRef<HTMLDivElement>();
     private sublistRef = createRef<HTMLDivElement>();
+    private dispatcherRef: string;
 
     constructor(props: IProps) {
         super(props);
@@ -99,6 +108,7 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
             isResizing: false,
         };
         this.state.notificationState.setRooms(this.props.rooms);
+        this.dispatcherRef = defaultDispatcher.register(this.onAction);
     }
 
     private get numTiles(): number {
@@ -117,17 +127,53 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
 
     public componentWillUnmount() {
         this.state.notificationState.destroy();
+        defaultDispatcher.unregister(this.dispatcherRef);
     }
 
+    private onAction = (payload: ActionPayload) => {
+        if (payload.action === "view_room" && payload.show_room_tile && this.props.rooms) {
+            // XXX: we have to do this a tick later because we have incorrect intermediate props during a room change
+            // where we lose the room we are changing from temporarily and then it comes back in an update right after.
+            setImmediate(() => {
+                const isCollapsed = this.props.layout.isCollapsed;
+                const roomIndex = this.props.rooms.findIndex((r) => r.roomId === payload.room_id);
+
+                if (isCollapsed && roomIndex > -1) {
+                    this.toggleCollapsed();
+                }
+                // extend the visible section to include the room if it is entirely invisible
+                if (roomIndex >= this.numVisibleTiles) {
+                    this.props.layout.visibleTiles = this.props.layout.tilesWithPadding(roomIndex + 1, MAX_PADDING_HEIGHT);
+                    this.forceUpdate(); // because the layout doesn't trigger a re-render
+                }
+            });
+        }
+    };
+
     private onAddRoom = (e) => {
         e.stopPropagation();
         if (this.props.onAddRoom) this.props.onAddRoom();
     };
 
-    private onResize = (e: React.MouseEvent, data: ResizeCallbackData) => {
-        const direction = e.movementY < 0 ? -1 : +1;
-        const tileDiff = this.props.layout.pixelsToTiles(Math.abs(e.movementY)) * direction;
-        this.props.layout.setVisibleTilesWithin(tileDiff, this.numTiles);
+    private onResize = (
+        e: MouseEvent | TouchEvent,
+        travelDirection: Direction,
+        refToElement: HTMLDivElement,
+        delta: { width: number, height: number }, // TODO: Use re-resizer's NumberSize when it is exposed as the type
+    ) => {
+        // Do some sanity checks, but in reality we shouldn't need these.
+        if (travelDirection !== "bottom") return;
+        if (delta.height === 0) return; // something went wrong, so just ignore it.
+
+        // NOTE: the movement in the MouseEvent (not present on a TouchEvent) is inaccurate
+        // for our purposes. The delta provided by the library is also a change *from when
+        // resizing started*, meaning it is fairly useless for us. This is why we just use
+        // the client height and run with it.
+
+        const heightBefore = this.props.layout.visibleTiles;
+        const heightInTiles = this.props.layout.pixelsToTiles(refToElement.clientHeight);
+        this.props.layout.setVisibleTilesWithin(heightInTiles, this.numTiles);
+        if (heightBefore === this.props.layout.visibleTiles) return; // no-op
         this.forceUpdate(); // because the layout doesn't trigger a re-render
     };
 
@@ -140,18 +186,28 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
     };
 
     private onShowAllClick = () => {
-        // TODO a11y keep focus somewhere useful: https://github.com/vector-im/riot-web/issues/14180
+        const numVisibleTiles = this.numVisibleTiles;
         this.props.layout.visibleTiles = this.props.layout.tilesWithPadding(this.numTiles, MAX_PADDING_HEIGHT);
         this.forceUpdate(); // because the layout doesn't trigger a re-render
+        setImmediate(this.focusRoomTile, numVisibleTiles); // focus the tile after the current bottom one
     };
 
     private onShowLessClick = () => {
-        // TODO a11y keep focus somewhere useful: https://github.com/vector-im/riot-web/issues/14180
         this.props.layout.visibleTiles = this.props.layout.defaultVisibleTiles;
         this.forceUpdate(); // because the layout doesn't trigger a re-render
+        // focus will flow to the show more button here
     };
 
-    private onOpenMenuClick = (ev: InputEvent) => {
+    private focusRoomTile = (index: number) => {
+        if (!this.sublistRef.current) return;
+        const elements = this.sublistRef.current.querySelectorAll<HTMLDivElement>(".mx_RoomTile2");
+        const element = elements && elements[index];
+        if (element) {
+            element.focus();
+        }
+    };
+
+    private onOpenMenuClick = (ev: React.MouseEvent) => {
         ev.preventDefault();
         ev.stopPropagation();
         const target = ev.target as HTMLButtonElement;
@@ -223,7 +279,11 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
 
         const possibleSticky = target.parentElement;
         const sublist = possibleSticky.parentElement.parentElement;
-        if (possibleSticky.classList.contains('mx_RoomSublist2_headerContainer_sticky')) {
+        const list = sublist.parentElement.parentElement;
+        // the scrollTop is capped at the height of the header in LeftPanel2
+        const isAtTop = list.scrollTop <= HEADER_HEIGHT;
+        const isSticky = possibleSticky.classList.contains('mx_RoomSublist2_headerContainer_sticky');
+        if (isSticky && !isAtTop) {
             // is sticky - jump to list
             sublist.scrollIntoView({behavior: 'smooth'});
         } else {
@@ -355,7 +415,7 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
 
             contextMenu = (
                 <ContextMenu
-                    chevronFace="none"
+                    chevronFace={ChevronFace.None}
                     left={this.state.contextMenuPosition.left}
                     top={this.state.contextMenuPosition.top + this.state.contextMenuPosition.height}
                     onFinished={this.onCloseMenu}
@@ -450,7 +510,6 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
                         </div>
                     );
 
-                    // TODO: a11y (see old component): https://github.com/vector-im/riot-web/issues/14180
                     // Note: the addRoomButton conditionally gets moved around
                     // the DOM depending on whether or not the list is minimized.
                     // If we're minimized, we want it below the header so it
@@ -521,12 +580,12 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
                 );
                 if (this.props.isMinimized) showMoreText = null;
                 showNButton = (
-                    <AccessibleButton onClick={this.onShowAllClick} className={showMoreBtnClasses} tabIndex={-1}>
+                    <RovingAccessibleButton onClick={this.onShowAllClick} className={showMoreBtnClasses}>
                         <span className='mx_RoomSublist2_showMoreButtonChevron mx_RoomSublist2_showNButtonChevron'>
                             {/* set by CSS masking */}
                         </span>
                         {showMoreText}
-                    </AccessibleButton>
+                    </RovingAccessibleButton>
                 );
             } else if (this.numTiles <= visibleTiles.length && this.numTiles > this.props.layout.defaultVisibleTiles) {
                 // we have all tiles visible - add a button to show less
@@ -536,21 +595,30 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
                     </span>
                 );
                 if (this.props.isMinimized) showLessText = null;
-                // TODO Roving tab index / treeitem?: https://github.com/vector-im/riot-web/issues/14180
                 showNButton = (
-                    <AccessibleButton onClick={this.onShowLessClick} className={showMoreBtnClasses} tabIndex={-1}>
+                    <RovingAccessibleButton onClick={this.onShowLessClick} className={showMoreBtnClasses}>
                         <span className='mx_RoomSublist2_showLessButtonChevron mx_RoomSublist2_showNButtonChevron'>
                             {/* set by CSS masking */}
                         </span>
                         {showLessText}
-                    </AccessibleButton>
+                    </RovingAccessibleButton>
                 );
             }
 
             // Figure out if we need a handle
-            let handles = ['s'];
+            const handles: Enable = {
+                bottom: true, // the only one we need, but the others must be explicitly false
+                bottomLeft: false,
+                bottomRight: false,
+                left: false,
+                right: false,
+                top: false,
+                topLeft: false,
+                topRight: false,
+            };
             if (layout.visibleTiles >= this.numTiles && this.numTiles <= layout.minVisibleTiles) {
-                handles = []; // no handles, we're at a minimum
+                // we're at a minimum, don't have a bottom handle
+                handles.bottom = false;
             }
 
             // We have to account for padding so we can accommodate a 'show more' button and
@@ -574,22 +642,25 @@ export default class RoomSublist2 extends React.Component<IProps, IState> {
             const tilesWithoutPadding = Math.min(relativeTiles, layout.visibleTiles);
             const tilesPx = layout.calculateTilesToPixelsMin(relativeTiles, tilesWithoutPadding, padding);
 
+            const dimensions = {
+                height: tilesPx,
+            };
             content = (
-                <ResizableBox
-                    width={-1}
-                    height={tilesPx}
-                    axis="y"
-                    minConstraints={[-1, minTilesPx]}
-                    maxConstraints={[-1, maxTilesPx]}
-                    resizeHandles={handles}
-                    onResize={this.onResize}
-                    className="mx_RoomSublist2_resizeBox"
+                <Resizable
+                    size={dimensions as any}
+                    minHeight={minTilesPx}
+                    maxHeight={maxTilesPx}
                     onResizeStart={this.onResizeStart}
                     onResizeStop={this.onResizeStop}
+                    onResize={this.onResize}
+                    handleWrapperClass="mx_RoomSublist2_resizerHandles"
+                    handleClasses={{bottom: "mx_RoomSublist2_resizerHandle"}}
+                    className="mx_RoomSublist2_resizeBox"
+                    enable={handles}
                 >
                     {visibleTiles}
                     {showNButton}
-                </ResizableBox>
+                </Resizable>
             );
         }
 
diff --git a/src/components/views/rooms/RoomTile2.tsx b/src/components/views/rooms/RoomTile2.tsx
index aae731cf49..4ecd6bb1ff 100644
--- a/src/components/views/rooms/RoomTile2.tsx
+++ b/src/components/views/rooms/RoomTile2.tsx
@@ -17,7 +17,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import React from "react";
+import React, {createRef} from "react";
 import { Room } from "matrix-js-sdk/src/models/room";
 import classNames from "classnames";
 import { RovingTabIndexWrapper } from "../../../accessibility/RovingTabIndex";
@@ -27,6 +27,7 @@ import { Key } from "../../../Keyboard";
 import ActiveRoomObserver from "../../../ActiveRoomObserver";
 import { _t } from "../../../languageHandler";
 import {
+    ChevronFace,
     ContextMenu,
     ContextMenuButton,
     MenuItemRadio,
@@ -52,6 +53,8 @@ import { NotificationColor } from "../../../stores/notifications/NotificationCol
 import { Volume } from "../../../RoomNotifsTypes";
 import RoomListStore from "../../../stores/room-list/RoomListStore2";
 import RoomListActions from "../../../actions/RoomListActions";
+import defaultDispatcher from "../../../dispatcher/dispatcher";
+import {ActionPayload} from "../../../dispatcher/payloads";
 
 // TODO: Remove banner on launch: https://github.com/vector-im/riot-web/issues/14231
 // TODO: Rename on launch: https://github.com/vector-im/riot-web/issues/14231
@@ -89,7 +92,7 @@ const contextMenuBelow = (elementRect: PartialDOMRect) => {
     // align the context menu's icons with the icon which opened the context menu
     const left = elementRect.left + window.pageXOffset - 9;
     const top = elementRect.bottom + window.pageYOffset + 17;
-    const chevronFace = "none";
+    const chevronFace = ChevronFace.None;
     return {left, top, chevronFace};
 };
 
@@ -120,6 +123,8 @@ const NotifOption: React.FC<INotifOptionProps> = ({active, onClick, iconClassNam
 };
 
 export default class RoomTile2 extends React.Component<IProps, IState> {
+    private dispatcherRef: string;
+    private roomTileRef = createRef<HTMLDivElement>();
     // TODO: a11y: https://github.com/vector-im/riot-web/issues/14180
 
     constructor(props: IProps) {
@@ -134,6 +139,7 @@ export default class RoomTile2 extends React.Component<IProps, IState> {
         };
 
         ActiveRoomObserver.addListener(this.props.room.roomId, this.onActiveRoomUpdate);
+        this.dispatcherRef = defaultDispatcher.register(this.onAction);
     }
 
     private get showContextMenu(): boolean {
@@ -144,12 +150,36 @@ export default class RoomTile2 extends React.Component<IProps, IState> {
         return !this.props.isMinimized && this.props.showMessagePreview;
     }
 
+    public componentDidMount() {
+        // when we're first rendered (or our sublist is expanded) make sure we are visible if we're active
+        if (this.state.selected) {
+            this.scrollIntoView();
+        }
+    }
+
     public componentWillUnmount() {
         if (this.props.room) {
             ActiveRoomObserver.removeListener(this.props.room.roomId, this.onActiveRoomUpdate);
         }
+        defaultDispatcher.unregister(this.dispatcherRef);
     }
 
+    private onAction = (payload: ActionPayload) => {
+        if (payload.action === "view_room" && payload.room_id === this.props.room.roomId && payload.show_room_tile) {
+            setImmediate(() => {
+                this.scrollIntoView();
+            });
+        }
+    };
+
+    private scrollIntoView = () => {
+        if (!this.roomTileRef.current) return;
+        this.roomTileRef.current.scrollIntoView({
+            block: "nearest",
+            behavior: "auto",
+        });
+    };
+
     private onTileMouseEnter = () => {
         this.setState({hover: true});
     };
@@ -163,7 +193,6 @@ export default class RoomTile2 extends React.Component<IProps, IState> {
         ev.stopPropagation();
         dis.dispatch({
             action: 'view_room',
-            // TODO: Support show_room_tile in new room list: https://github.com/vector-im/riot-web/issues/14233
             show_room_tile: true, // make sure the room is visible in the list
             room_id: this.props.room.roomId,
             clear_search: (ev && (ev.key === Key.ENTER || ev.key === Key.SPACE)),
@@ -174,7 +203,7 @@ export default class RoomTile2 extends React.Component<IProps, IState> {
         this.setState({selected: isActive});
     };
 
-    private onNotificationsMenuOpenClick = (ev: InputEvent) => {
+    private onNotificationsMenuOpenClick = (ev: React.MouseEvent) => {
         ev.preventDefault();
         ev.stopPropagation();
         const target = ev.target as HTMLButtonElement;
@@ -185,7 +214,7 @@ export default class RoomTile2 extends React.Component<IProps, IState> {
         this.setState({notificationsMenuPosition: null});
     };
 
-    private onGeneralMenuOpenClick = (ev: InputEvent) => {
+    private onGeneralMenuOpenClick = (ev: React.MouseEvent) => {
         ev.preventDefault();
         ev.stopPropagation();
         const target = ev.target as HTMLButtonElement;
@@ -414,7 +443,6 @@ export default class RoomTile2 extends React.Component<IProps, IState> {
 
     public render(): React.ReactElement {
         // TODO: Invites: https://github.com/vector-im/riot-web/issues/14198
-        // TODO: a11y proper: https://github.com/vector-im/riot-web/issues/14180
 
         const classes = classNames({
             'mx_RoomTile2': true,
@@ -504,7 +532,7 @@ export default class RoomTile2 extends React.Component<IProps, IState> {
 
         return (
             <React.Fragment>
-                <RovingTabIndexWrapper>
+                <RovingTabIndexWrapper inputRef={this.roomTileRef}>
                     {({onFocus, isActive, ref}) =>
                         <AccessibleButton
                             onFocus={onFocus}
diff --git a/src/settings/Settings.js b/src/settings/Settings.js
index 58d9ed4f31..0011ecfccd 100644
--- a/src/settings/Settings.js
+++ b/src/settings/Settings.js
@@ -478,13 +478,13 @@ export const SETTINGS = {
             deny: [],
         },
     },
-    // TODO: Remove setting: https://github.com/vector-im/riot-web/issues/14231
+    // TODO: Remove setting: https://github.com/vector-im/riot-web/issues/14373
     "RoomList.orderAlphabetically": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         displayName: _td("Order rooms by name"),
         default: false,
     },
-    // TODO: Remove setting: https://github.com/vector-im/riot-web/issues/14231
+    // TODO: Remove setting: https://github.com/vector-im/riot-web/issues/14373
     "RoomList.orderByImportance": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         displayName: _td("Show rooms with unread notifications first"),
diff --git a/src/settings/handlers/RoomSettingsHandler.js b/src/settings/handlers/RoomSettingsHandler.js
index d8e775742c..00dd5b8bec 100644
--- a/src/settings/handlers/RoomSettingsHandler.js
+++ b/src/settings/handlers/RoomSettingsHandler.js
@@ -43,11 +43,14 @@ export default class RoomSettingsHandler extends MatrixClientBackedSettingsHandl
         const roomId = event.getRoomId();
         const room = this.client.getRoom(roomId);
 
-        // Note: the tests often fire setting updates that don't have rooms in the store, so
-        // we fail softly here. We shouldn't assume that the state being fired is current
-        // state, but we also don't need to explode just because we didn't find a room.
-        if (!room) console.warn(`Unknown room caused setting update: ${roomId}`);
-        if (room && state !== room.currentState) return; // ignore state updates which are not current
+        // Note: in tests and during the encryption setup on initial load we might not have
+        // rooms in the store, so we just quietly ignore the problem. If we log it then we'll
+        // just end up spamming the logs a few thousand times. It is perfectly fine for us
+        // to ignore the problem as the app will not have loaded enough to care yet.
+        if (!room) return;
+
+        // ignore state updates which are not current
+        if (room && state !== room.currentState) return;
 
         if (event.getType() === "org.matrix.room.preview_urls") {
             let val = event.getContent()['disable'];
diff --git a/src/stores/room-list/ListLayout.ts b/src/stores/room-list/ListLayout.ts
index f31e92b8ae..99674fe74f 100644
--- a/src/stores/room-list/ListLayout.ts
+++ b/src/stores/room-list/ListLayout.ts
@@ -89,11 +89,12 @@ export class ListLayout {
         return 5 + RESIZER_BOX_FACTOR;
     }
 
-    public setVisibleTilesWithin(diff: number, maxPossible: number) {
-        if (this.visibleTiles > maxPossible) {
-            this.visibleTiles = maxPossible + diff;
+    public setVisibleTilesWithin(newVal: number, maxPossible: number) {
+        maxPossible = maxPossible + RESIZER_BOX_FACTOR;
+        if (newVal > maxPossible) {
+            this.visibleTiles = maxPossible;
         } else {
-            this.visibleTiles += diff;
+            this.visibleTiles = newVal;
         }
     }
 
diff --git a/src/stores/room-list/RoomListStore2.ts b/src/stores/room-list/RoomListStore2.ts
index e5205f6051..82c419d79d 100644
--- a/src/stores/room-list/RoomListStore2.ts
+++ b/src/stores/room-list/RoomListStore2.ts
@@ -31,6 +31,7 @@ import RoomViewStore from "../RoomViewStore";
 import { Algorithm, LIST_UPDATED_EVENT } from "./algorithms/Algorithm";
 import { EffectiveMembership, getEffectiveMembership } from "./membership";
 import { ListLayout } from "./ListLayout";
+import { isNullOrUndefined } from "matrix-js-sdk/src/utils";
 
 interface IState {
     tagsEnabled?: boolean;
@@ -221,9 +222,6 @@ export class RoomListStore2 extends AsyncStore<ActionPayload> {
             }
             // TODO: Remove debug: https://github.com/vector-im/riot-web/issues/14035
             console.log(`[RoomListDebug] Decrypted timeline event ${eventPayload.event.getId()} in ${roomId}`);
-            // TODO: Verify that e2e rooms are handled on init: https://github.com/vector-im/riot-web/issues/14238
-            // It seems like when viewing the room the timeline is decrypted, rather than at startup. This could
-            // cause inaccuracies with the list ordering. We may have to decrypt the last N messages of every room :(
             await this.handleRoomUpdate(room, RoomUpdateCause.Timeline);
         } else if (payload.action === 'MatrixActions.accountData' && payload.event_type === 'm.direct') {
             const eventPayload = (<any>payload); // TODO: Type out the dispatcher types
@@ -321,6 +319,28 @@ export class RoomListStore2 extends AsyncStore<ActionPayload> {
         return <SortAlgorithm>localStorage.getItem(`mx_tagSort_${tagId}`);
     }
 
+    // logic must match calculateListOrder
+    private calculateTagSorting(tagId: TagID): SortAlgorithm {
+        const defaultSort = SortAlgorithm.Alphabetic;
+        const settingAlphabetical = SettingsStore.getValue("RoomList.orderAlphabetically", null, true);
+        const definedSort = this.getTagSorting(tagId);
+        const storedSort = this.getStoredTagSorting(tagId);
+
+        // We use the following order to determine which of the 4 flags to use:
+        // Stored > Settings > Defined > Default
+
+        let tagSort = defaultSort;
+        if (storedSort) {
+            tagSort = storedSort;
+        } else if (!isNullOrUndefined(settingAlphabetical)) {
+            tagSort = settingAlphabetical ? SortAlgorithm.Alphabetic : SortAlgorithm.Recent;
+        } else if (definedSort) {
+            tagSort = definedSort;
+        } // else default (already set)
+
+        return tagSort;
+    }
+
     public async setListOrder(tagId: TagID, order: ListAlgorithm) {
         await this.algorithm.setListOrdering(tagId, order);
         // TODO: Per-account? https://github.com/vector-im/riot-web/issues/14114
@@ -337,19 +357,35 @@ export class RoomListStore2 extends AsyncStore<ActionPayload> {
         return <ListAlgorithm>localStorage.getItem(`mx_listOrder_${tagId}`);
     }
 
-    private async updateAlgorithmInstances() {
-        const defaultSort = SortAlgorithm.Alphabetic;
+    // logic must match calculateTagSorting
+    private calculateListOrder(tagId: TagID): ListAlgorithm {
         const defaultOrder = ListAlgorithm.Natural;
+        const settingImportance = SettingsStore.getValue("RoomList.orderByImportance", null, true);
+        const definedOrder = this.getListOrder(tagId);
+        const storedOrder = this.getStoredListOrder(tagId);
 
+        // We use the following order to determine which of the 4 flags to use:
+        // Stored > Settings > Defined > Default
+
+        let listOrder = defaultOrder;
+        if (storedOrder) {
+            listOrder = storedOrder;
+        } else if (!isNullOrUndefined(settingImportance)) {
+            listOrder = settingImportance ? ListAlgorithm.Importance : ListAlgorithm.Natural;
+        } else if (definedOrder) {
+            listOrder = definedOrder;
+        } // else default (already set)
+
+        return listOrder;
+    }
+
+    private async updateAlgorithmInstances() {
         for (const tag of Object.keys(this.orderedLists)) {
             const definedSort = this.getTagSorting(tag);
             const definedOrder = this.getListOrder(tag);
 
-            const storedSort = this.getStoredTagSorting(tag);
-            const storedOrder = this.getStoredListOrder(tag);
-
-            const tagSort = storedSort ? storedSort : (definedSort ? definedSort : defaultSort);
-            const listOrder = storedOrder ? storedOrder : (definedOrder ? definedOrder : defaultOrder);
+            const tagSort = this.calculateTagSorting(tag);
+            const listOrder = this.calculateListOrder(tag);
 
             if (tagSort !== definedSort) {
                 await this.setTagSorting(tag, tagSort);
@@ -378,8 +414,8 @@ export class RoomListStore2 extends AsyncStore<ActionPayload> {
         const sorts: ITagSortingMap = {};
         const orders: IListOrderingMap = {};
         for (const tagId of OrderedDefaultTagIDs) {
-            sorts[tagId] = this.getStoredTagSorting(tagId) || SortAlgorithm.Alphabetic;
-            orders[tagId] = this.getStoredListOrder(tagId) || ListAlgorithm.Natural;
+            sorts[tagId] = this.calculateTagSorting(tagId);
+            orders[tagId] = this.calculateListOrder(tagId);
         }
 
         if (this.state.tagsEnabled) {
diff --git a/src/stores/room-list/algorithms/Algorithm.ts b/src/stores/room-list/algorithms/Algorithm.ts
index d5f2ed0053..8c7bbc8615 100644
--- a/src/stores/room-list/algorithms/Algorithm.ts
+++ b/src/stores/room-list/algorithms/Algorithm.ts
@@ -109,6 +109,7 @@ export class Algorithm extends EventEmitter {
     }
 
     public getTagSorting(tagId: TagID): SortAlgorithm {
+        if (!this.sortAlgorithms) return null;
         return this.sortAlgorithms[tagId];
     }
 
@@ -125,6 +126,7 @@ export class Algorithm extends EventEmitter {
     }
 
     public getListOrdering(tagId: TagID): ListAlgorithm {
+        if (!this.listAlgorithms) return null;
         return this.listAlgorithms[tagId];
     }
 
@@ -501,13 +503,9 @@ export class Algorithm extends EventEmitter {
         // Split out the easy rooms first (leave and invite)
         const memberships = splitRoomsByMembership(rooms);
         for (const room of memberships[EffectiveMembership.Invite]) {
-            // TODO: Remove debug: https://github.com/vector-im/riot-web/issues/14035
-            console.log(`[DEBUG] "${room.name}" (${room.roomId}) is an Invite`);
             newTags[DefaultTagID.Invite].push(room);
         }
         for (const room of memberships[EffectiveMembership.Leave]) {
-            // TODO: Remove debug: https://github.com/vector-im/riot-web/issues/14035
-            console.log(`[DEBUG] "${room.name}" (${room.roomId}) is Historical`);
             newTags[DefaultTagID.Archived].push(room);
         }
 
@@ -518,11 +516,7 @@ export class Algorithm extends EventEmitter {
             let inTag = false;
             if (tags.length > 0) {
                 for (const tag of tags) {
-                    // TODO: Remove debug: https://github.com/vector-im/riot-web/issues/14035
-                    console.log(`[DEBUG] "${room.name}" (${room.roomId}) is tagged as ${tag}`);
                     if (!isNullOrUndefined(newTags[tag])) {
-                        // TODO: Remove debug: https://github.com/vector-im/riot-web/issues/14035
-                        console.log(`[DEBUG] "${room.name}" (${room.roomId}) is tagged with VALID tag ${tag}`);
                         newTags[tag].push(room);
                         inTag = true;
                     }
@@ -530,11 +524,11 @@ export class Algorithm extends EventEmitter {
             }
 
             if (!inTag) {
-                // TODO: Determine if DM and push there instead: https://github.com/vector-im/riot-web/issues/14236
-                newTags[DefaultTagID.Untagged].push(room);
-
-                // TODO: Remove debug: https://github.com/vector-im/riot-web/issues/14035
-                console.log(`[DEBUG] "${room.name}" (${room.roomId}) is Untagged`);
+                if (DMRoomMap.shared().getUserIdForRoomId(room.roomId)) {
+                    newTags[DefaultTagID.DM].push(room);
+                } else {
+                    newTags[DefaultTagID.Untagged].push(room);
+                }
             }
         }
 
diff --git a/src/stores/room-list/previews/MessageEventPreview.ts b/src/stores/room-list/previews/MessageEventPreview.ts
index 86ec4c539b..86cb51ef15 100644
--- a/src/stores/room-list/previews/MessageEventPreview.ts
+++ b/src/stores/room-list/previews/MessageEventPreview.ts
@@ -20,6 +20,7 @@ import { MatrixEvent } from "matrix-js-sdk/src/models/event";
 import { _t } from "../../../languageHandler";
 import { getSenderName, isSelf, shouldPrefixMessagesIn } from "./utils";
 import ReplyThread from "../../../components/views/elements/ReplyThread";
+import { sanitizedHtmlNodeInnerText } from "../../../HtmlUtils";
 
 export class MessageEventPreview implements IPreview {
     public getTextFor(event: MatrixEvent, tagId?: TagID): string {
@@ -36,14 +37,27 @@ export class MessageEventPreview implements IPreview {
         const msgtype = eventContent['msgtype'];
         if (!body || !msgtype) return null; // invalid event, no preview
 
+        const hasHtml = eventContent.format === "org.matrix.custom.html" && eventContent.formatted_body;
+        if (hasHtml) {
+            body = eventContent.formatted_body;
+        }
+
         // XXX: Newer relations have a getRelation() function which is not compatible with replies.
         const mRelatesTo = event.getWireContent()['m.relates_to'];
         if (mRelatesTo && mRelatesTo['m.in_reply_to']) {
             // If this is a reply, get the real reply and use that
-            body = (ReplyThread.stripPlainReply(body) || '').trim();
+            if (hasHtml) {
+                body = (ReplyThread.stripHTMLReply(body) || '').trim();
+            } else {
+                body = (ReplyThread.stripPlainReply(body) || '').trim();
+            }
             if (!body) return null; // invalid event, no preview
         }
 
+        if (hasHtml) {
+            body = sanitizedHtmlNodeInnerText(body);
+        }
+
         if (msgtype === 'm.emote') {
             return _t("%(senderName)s %(emote)s", {senderName: getSenderName(event), emote: body});
         }
diff --git a/yarn.lock b/yarn.lock
index d8106febab..f3dc163b00 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1308,6 +1308,13 @@
   resolved "https://registry.yarnpkg.com/@types/json-schema/-/json-schema-7.0.4.tgz#38fd73ddfd9b55abb1e1b2ed578cb55bd7b7d339"
   integrity sha512-8+KAKzEvSUdeo+kmqnKrqgeE+LcA0tjYWFY7RPProVYwnqDjukzO+3b6dLD56rYX5TdWejnEOLJYOIeh4CXKuA==
 
+"@types/linkifyjs@^2.1.3":
+  version "2.1.3"
+  resolved "https://registry.yarnpkg.com/@types/linkifyjs/-/linkifyjs-2.1.3.tgz#80195c3c88c5e75d9f660e3046ce4a42be2c2fa4"
+  integrity sha512-V3Xt9wgaOvDPXcpOy3dC8qXCxy3cs0Lr/Hqgd9Bi6m3sf/vpbpTtfmVR0LJklrqYEjaAmc7e3Xh/INT2rCAKjQ==
+  dependencies:
+    "@types/react" "*"
+
 "@types/lodash@^4.14.152":
   version "4.14.155"
   resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.155.tgz#e2b4514f46a261fd11542e47519c20ebce7bc23a"
@@ -1372,6 +1379,13 @@
     "@types/prop-types" "*"
     csstype "^2.2.0"
 
+"@types/sanitize-html@^1.23.3":
+  version "1.23.3"
+  resolved "https://registry.yarnpkg.com/@types/sanitize-html/-/sanitize-html-1.23.3.tgz#26527783aba3bf195ad8a3c3e51bd3713526fc0d"
+  integrity sha512-Isg8N0ifKdDq6/kaNlIcWfapDXxxquMSk2XC5THsOICRyOIhQGds95XH75/PL/g9mExi4bL8otIqJM/Wo96WxA==
+  dependencies:
+    htmlparser2 "^4.1.0"
+
 "@types/stack-utils@^1.0.1":
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/@types/stack-utils/-/stack-utils-1.0.1.tgz#0a851d3bd96498fa25c33ab7278ed3bd65f06c3e"
@@ -2499,7 +2513,7 @@ class-utils@^0.3.5:
     isobject "^3.0.0"
     static-extend "^0.1.1"
 
-classnames@^2.1.2, classnames@^2.2.5:
+classnames@^2.1.2:
   version "2.2.6"
   resolved "https://registry.yarnpkg.com/classnames/-/classnames-2.2.6.tgz#43935bffdd291f326dad0a205309b38d00f650ce"
   integrity sha512-JR/iSQOSt+LQIWwrwEzJ9uk0xfN3mTVYMwt1Ir5mUcSN6pU+V4zQFFaJsclJbPuAUQH+yfWef6tm7l1quW3C8Q==
@@ -3779,6 +3793,11 @@ fast-levenshtein@~2.0.6:
   resolved "https://registry.yarnpkg.com/fast-levenshtein/-/fast-levenshtein-2.0.6.tgz#3d8a5c66883a16a30ca8643e851f19baa7797917"
   integrity sha1-PYpcZog6FqMMqGQ+hR8Zuqd5eRc=
 
+fast-memoize@^2.5.1:
+  version "2.5.2"
+  resolved "https://registry.yarnpkg.com/fast-memoize/-/fast-memoize-2.5.2.tgz#79e3bb6a4ec867ea40ba0e7146816f6cdce9b57e"
+  integrity sha512-Ue0LwpDYErFbmNnZSF0UH6eImUwDmogUO1jyE+JbN2gsQz/jICm1Ve7t9QT0rNSsfJt+Hs4/S3GnsDVjL4HVrw==
+
 fb-watchman@^2.0.0:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/fb-watchman/-/fb-watchman-2.0.1.tgz#fc84fb39d2709cf3ff6d743706157bb5708a8a85"
@@ -6882,7 +6901,7 @@ prop-types-exact@^1.2.0:
     object.assign "^4.1.0"
     reflect.ownkeys "^0.2.0"
 
-prop-types@15.x, prop-types@^15.5.8, prop-types@^15.6.0, prop-types@^15.6.1, prop-types@^15.6.2, prop-types@^15.7.2:
+prop-types@^15.5.8, prop-types@^15.6.0, prop-types@^15.6.1, prop-types@^15.6.2, prop-types@^15.7.2:
   version "15.7.2"
   resolved "https://registry.yarnpkg.com/prop-types/-/prop-types-15.7.2.tgz#52c41e75b8c87e72b9d9360e0206b99dcbffa6c5"
   integrity sha512-8QQikdH7//R2vurIJSutZ1smHYTcLpRWEOlHnzcWHmBYrOGUysKwSsrC89BCiFj3CbrfJ/nXFdJepOVrY1GCHQ==
@@ -7053,6 +7072,13 @@ rc@1.2.8, rc@^1.2.8:
     minimist "^1.2.0"
     strip-json-comments "~2.0.1"
 
+re-resizable@^6.5.2:
+  version "6.5.2"
+  resolved "https://registry.yarnpkg.com/re-resizable/-/re-resizable-6.5.2.tgz#7eb1928c673285d4dcf654211e47acb9a3801c3e"
+  integrity sha512-Pjo3ydkr/meTr6j3YZqyv+9fRS5UNOj5SaAI06gHFQ35BnpsZKmwNvupCnbo11gjQ1I62Uy+UzlHLO9xPQEuWQ==
+  dependencies:
+    fast-memoize "^2.5.1"
+
 react-beautiful-dnd@^4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/react-beautiful-dnd/-/react-beautiful-dnd-4.0.1.tgz#3b0a49bf6be75af351176c904f012611dd292b81"
@@ -7086,14 +7112,6 @@ react-dom@^16.9.0:
     prop-types "^15.6.2"
     scheduler "^0.19.1"
 
-react-draggable@^4.0.3:
-  version "4.4.2"
-  resolved "https://registry.yarnpkg.com/react-draggable/-/react-draggable-4.4.2.tgz#f3cefecee25f467f865144cda0d066e5f05f94a0"
-  integrity sha512-zLQs4R4bnBCGnCVTZiD8hPsHtkiJxgMpGDlRESM+EHQo8ysXhKJ2GKdJ8UxxLJdRVceX1j19jy+hQS2wHislPQ==
-  dependencies:
-    classnames "^2.2.5"
-    prop-types "^15.6.0"
-
 react-focus-lock@^2.2.1:
   version "2.3.1"
   resolved "https://registry.yarnpkg.com/react-focus-lock/-/react-focus-lock-2.3.1.tgz#9d5d85899773609c7eefa4fc54fff6a0f5f2fc47"
@@ -7138,14 +7156,6 @@ react-redux@^5.0.6:
     react-is "^16.6.0"
     react-lifecycles-compat "^3.0.0"
 
-react-resizable@^1.10.1:
-  version "1.10.1"
-  resolved "https://registry.yarnpkg.com/react-resizable/-/react-resizable-1.10.1.tgz#f0c2cf1d83b3470b87676ce6d6b02bbe3f4d8cd4"
-  integrity sha512-Jd/bKOKx6+19NwC4/aMLRu/J9/krfxlDnElP41Oc+oLiUWs/zwV1S9yBfBZRnqAwQb6vQ/HRSk3bsSWGSgVbpw==
-  dependencies:
-    prop-types "15.x"
-    react-draggable "^4.0.3"
-
 react-test-renderer@^16.0.0-0, react-test-renderer@^16.9.0:
   version "16.13.1"
   resolved "https://registry.yarnpkg.com/react-test-renderer/-/react-test-renderer-16.13.1.tgz#de25ea358d9012606de51e012d9742e7f0deabc1"