diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 9872ff320bd1..77c299b6b7f8 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -1166,6 +1166,10 @@
     "message": "Join Call",
     "description": "Button label in the call lobby for joining a call"
   },
+  "calling__return": {
+    "message": "Return to Call",
+    "description": "Button label in the call lobby for returning to a call"
+  },
   "calling__call-is-full": {
     "message": "Call is full",
     "description": "Button label in the call lobby when you can't join because the call is full"
@@ -3083,6 +3087,42 @@
       }
     }
   },
+  "calling__call-notification__ended": {
+    "message": "The group call has ended",
+    "description": "Notification message when a group call has ended"
+  },
+  "calling__call-notification__started-by-someone": {
+    "message": "A group call was started",
+    "description": "Notification message when a group call has started, but we don't know who started it"
+  },
+  "calling__call-notification__started-by-you": {
+    "message": "You started a group call",
+    "description": "Notification message when a group call has started by you"
+  },
+  "calling__call-notification__started": {
+    "message": "$name$ started a group call",
+    "description": "Notification message when a group call has started",
+    "placeholders": {
+      "name": {
+        "content": "$1",
+        "example": "Alice"
+      }
+    }
+  },
+  "calling__call-notification__button__in-another-call-tooltip": {
+    "message": "You are already in a call",
+    "description": "Tooltip in disabled notification button when you're on another call"
+  },
+  "calling__call-notification__button__call-full-tooltip": {
+    "message": "Call has reached capacity of $max$ participants",
+    "description": "Tooltip in disabled notification button when the call is full",
+    "placeholders": {
+      "max": {
+        "content": "$1",
+        "example": "5"
+      }
+    }
+  },
   "calling__pip--on": {
     "message": "Minimize call",
     "description": "Title for picture-in-picture toggle"
diff --git a/js/modules/signal.js b/js/modules/signal.js
index 1e281ae28df2..276d26342e6a 100644
--- a/js/modules/signal.js
+++ b/js/modules/signal.js
@@ -57,9 +57,6 @@ const {
 const {
   StagedLinkPreview,
 } = require('../../ts/components/conversation/StagedLinkPreview');
-const {
-  getCallingNotificationText,
-} = require('../../ts/components/conversation/CallingNotification');
 
 // State
 const { createTimeline } = require('../../ts/state/roots/createTimeline');
@@ -310,7 +307,6 @@ exports.setup = (options = {}) => {
     ContactModal,
     Emojify,
     ErrorModal,
-    getCallingNotificationText,
     Lightbox,
     LightboxGallery,
     MediaGallery,
diff --git a/stylesheets/_mixins.scss b/stylesheets/_mixins.scss
index bdef54933c78..9aa5e1a8a7bf 100644
--- a/stylesheets/_mixins.scss
+++ b/stylesheets/_mixins.scss
@@ -393,3 +393,39 @@
 
   @include button-focus-outline;
 }
+
+@mixin button-green {
+  $background-color: $color-accent-green;
+
+  background-color: $background-color;
+  color: $color-white;
+
+  &:active {
+    // We need to include all four here for specificity precedence
+
+    @include mouse-mode {
+      background-color: mix($color-black, $background-color, 25%);
+    }
+    @include dark-mouse-mode {
+      background-color: mix($color-white, $background-color, 25%);
+    }
+
+    @include keyboard-mode {
+      background-color: mix($color-black, $background-color, 25%);
+    }
+    @include dark-keyboard-mode {
+      background-color: mix($color-white, $background-color, 25%);
+    }
+  }
+
+  &[disabled] {
+    opacity: 0.6;
+  }
+
+  @include button-focus-outline;
+}
+
+@mixin button-small {
+  border-radius: 9999px; // This ensures the borders are completely rounded. (A value like 100% would make it an ellipse.)
+  padding: 7px 14px;
+}
diff --git a/stylesheets/_modules.scss b/stylesheets/_modules.scss
index 65ae3f7b7dbc..54bf6c938e41 100644
--- a/stylesheets/_modules.scss
+++ b/stylesheets/_modules.scss
@@ -2432,6 +2432,16 @@ $timer-icons: '55', '50', '45', '40', '35', '30', '25', '20', '15', '10', '05',
       color: $color-gray-05;
     }
   }
+
+  &__button {
+    @include button-reset;
+    @include button-small;
+    @include button-green;
+    @include font-body-1-bold;
+
+    display: block;
+    margin: 0.5rem auto 0 auto;
+  }
 }
 
 .module-safety-number__bold-name {
diff --git a/ts/components/Tooltip.tsx b/ts/components/Tooltip.tsx
index 5668aeeb3618..373f3b0edb0d 100644
--- a/ts/components/Tooltip.tsx
+++ b/ts/components/Tooltip.tsx
@@ -2,9 +2,76 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import React from 'react';
+import { noop } from 'lodash';
 import { Manager, Reference, Popper } from 'react-popper';
 import { Theme, themeClassName } from '../util/theme';
 
+interface EventWrapperPropsType {
+  children: React.ReactNode;
+  onHoverChanged: (_: boolean) => void;
+}
+
+// React doesn't reliably fire `onMouseLeave` or `onMouseOut` events if wrapping a
+//   disabled button. This uses native browser events to avoid that.
+//
+// See <https://lecstor.com/react-disabled-button-onmouseleave/>.
+const TooltipEventWrapper = React.forwardRef<
+  HTMLSpanElement,
+  EventWrapperPropsType
+>(({ onHoverChanged, children }, ref) => {
+  const wrapperRef = React.useRef<HTMLSpanElement | null>(null);
+
+  React.useEffect(() => {
+    const wrapperEl = wrapperRef.current;
+
+    if (!wrapperEl) {
+      return noop;
+    }
+
+    const on = () => {
+      onHoverChanged(true);
+    };
+    const off = () => {
+      onHoverChanged(false);
+    };
+
+    wrapperEl.addEventListener('focus', on);
+    wrapperEl.addEventListener('blur', off);
+    wrapperEl.addEventListener('mouseenter', on);
+    wrapperEl.addEventListener('mouseleave', off);
+
+    return () => {
+      wrapperEl.removeEventListener('focus', on);
+      wrapperEl.removeEventListener('blur', off);
+      wrapperEl.removeEventListener('mouseenter', on);
+      wrapperEl.removeEventListener('mouseleave', off);
+    };
+  }, [onHoverChanged]);
+
+  return (
+    <span
+      // This is a forward ref that also needs a ref of its own, so we set both here.
+      ref={el => {
+        wrapperRef.current = el;
+
+        // This is a simplified version of [what React does][0] to set a ref.
+        // [0]: https://github.com/facebook/react/blob/29b7b775f2ecf878eaf605be959d959030598b07/packages/react-reconciler/src/ReactFiberCommitWork.js#L661-L677
+        if (typeof ref === 'function') {
+          ref(el);
+        } else if (ref) {
+          // I believe the types for `ref` are wrong in this case, as `ref.current` should
+          //   not be `readonly`. That's why we do this cast. See [the React source][1].
+          // [1]: https://github.com/facebook/react/blob/29b7b775f2ecf878eaf605be959d959030598b07/packages/shared/ReactTypes.js#L78-L80
+          // eslint-disable-next-line no-param-reassign
+          (ref as React.MutableRefObject<HTMLSpanElement | null>).current = el;
+        }
+      }}
+    >
+      {children}
+    </span>
+  );
+});
+
 export enum TooltipPlacement {
   Top = 'top',
   Right = 'right',
@@ -26,8 +93,9 @@ export const Tooltip: React.FC<PropsType> = ({
   sticky,
   theme,
 }) => {
-  const isSticky = Boolean(sticky);
-  const [showTooltip, setShowTooltip] = React.useState(isSticky);
+  const [isHovering, setIsHovering] = React.useState(false);
+
+  const showTooltip = isHovering || Boolean(sticky);
 
   const tooltipTheme = theme ? themeClassName(theme) : undefined;
 
@@ -35,31 +103,9 @@ export const Tooltip: React.FC<PropsType> = ({
     <Manager>
       <Reference>
         {({ ref }) => (
-          <span
-            onBlur={() => {
-              if (!isSticky) {
-                setShowTooltip(false);
-              }
-            }}
-            onFocus={() => {
-              if (!isSticky) {
-                setShowTooltip(true);
-              }
-            }}
-            onMouseEnter={() => {
-              if (!isSticky) {
-                setShowTooltip(true);
-              }
-            }}
-            onMouseLeave={() => {
-              if (!isSticky) {
-                setShowTooltip(false);
-              }
-            }}
-            ref={ref}
-          >
+          <TooltipEventWrapper ref={ref} onHoverChanged={setIsHovering}>
             {children}
-          </span>
+          </TooltipEventWrapper>
         )}
       </Reference>
       <Popper placement={direction}>
diff --git a/ts/components/conversation/CallingNotification.tsx b/ts/components/conversation/CallingNotification.tsx
index 76d736be294c..933c8e031cb6 100644
--- a/ts/components/conversation/CallingNotification.tsx
+++ b/ts/components/conversation/CallingNotification.tsx
@@ -1,90 +1,168 @@
 // Copyright 2020 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
-import React from 'react';
+import React, { useState, useRef, useEffect } from 'react';
+import Measure from 'react-measure';
 
 import { Timestamp } from './Timestamp';
 import { LocalizerType } from '../../types/Util';
-import { CallHistoryDetailsType } from '../../types/Calling';
+import { CallMode } from '../../types/Calling';
+import {
+  CallingNotificationType,
+  getCallingNotificationText,
+} from '../../util/callingNotification';
+import { missingCaseError } from '../../util/missingCaseError';
+import { Tooltip, TooltipPlacement } from '../Tooltip';
 
-export type PropsData = {
-  // Can be undefined because it comes from JS.
-  callHistoryDetails?: CallHistoryDetailsType;
-};
+export interface PropsActionsType {
+  messageSizeChanged: (messageId: string, conversationId: string) => void;
+  returnToActiveCall: () => void;
+  startCallingLobby: (_: {
+    conversationId: string;
+    isVideoCall: boolean;
+  }) => void;
+}
 
 type PropsHousekeeping = {
   i18n: LocalizerType;
+  conversationId: string;
+  messageId: string;
 };
 
-type Props = PropsData & PropsHousekeeping;
+type PropsType = CallingNotificationType & PropsActionsType & PropsHousekeeping;
 
-export function getCallingNotificationText(
-  callHistoryDetails: CallHistoryDetailsType,
-  i18n: LocalizerType
-): string {
-  const {
-    wasIncoming,
-    wasVideoCall,
-    wasDeclined,
-    acceptedTime,
-  } = callHistoryDetails;
-  const wasAccepted = Boolean(acceptedTime);
+export const CallingNotification: React.FC<PropsType> = React.memo(props => {
+  const { conversationId, i18n, messageId, messageSizeChanged } = props;
 
-  if (wasIncoming) {
-    if (wasDeclined) {
-      if (wasVideoCall) {
-        return i18n('declinedIncomingVideoCall');
-      }
-      return i18n('declinedIncomingAudioCall');
-    }
-    if (wasAccepted) {
-      if (wasVideoCall) {
-        return i18n('acceptedIncomingVideoCall');
-      }
-      return i18n('acceptedIncomingAudioCall');
-    }
-    if (wasVideoCall) {
-      return i18n('missedIncomingVideoCall');
-    }
-    return i18n('missedIncomingAudioCall');
-  }
-  if (wasAccepted) {
-    if (wasVideoCall) {
-      return i18n('acceptedOutgoingVideoCall');
-    }
-    return i18n('acceptedOutgoingAudioCall');
-  }
-  if (wasVideoCall) {
-    return i18n('missedOrDeclinedOutgoingVideoCall');
-  }
-  return i18n('missedOrDeclinedOutgoingAudioCall');
-}
+  const previousHeightRef = useRef<null | number>(null);
+  const [height, setHeight] = useState<null | number>(null);
 
-export const CallingNotification = (props: Props): JSX.Element | null => {
-  const { callHistoryDetails, i18n } = props;
-  if (!callHistoryDetails) {
+  useEffect(() => {
+    if (height === null) {
+      return;
+    }
+
+    if (
+      previousHeightRef.current !== null &&
+      height !== previousHeightRef.current
+    ) {
+      messageSizeChanged(messageId, conversationId);
+    }
+
+    previousHeightRef.current = height;
+  }, [height, conversationId, messageId, messageSizeChanged]);
+
+  let timestamp: number;
+  let callType: 'audio' | 'video';
+  switch (props.callMode) {
+    case CallMode.Direct:
+      timestamp = props.acceptedTime || props.endedTime;
+      callType = props.wasVideoCall ? 'video' : 'audio';
+      break;
+    case CallMode.Group:
+      timestamp = props.startedTime;
+      callType = 'video';
+      break;
+    default:
+      window.log.error(missingCaseError(props));
+      return null;
+  }
+
+  return (
+    <Measure
+      bounds
+      onResize={({ bounds }) => {
+        if (!bounds) {
+          window.log.error('We should be measuring the bounds');
+          return;
+        }
+        setHeight(bounds.height);
+      }}
+    >
+      {({ measureRef }) => (
+        <div
+          className={`module-message-calling--notification module-message-calling--${callType}`}
+          ref={measureRef}
+        >
+          <div className={`module-message-calling--${callType}__icon`} />
+          {getCallingNotificationText(props, i18n)}
+          <div>
+            <Timestamp
+              i18n={i18n}
+              timestamp={timestamp}
+              extended
+              direction="outgoing"
+              withImageNoCaption={false}
+              withSticker={false}
+              withTapToViewExpired={false}
+              module="module-message__metadata__date"
+            />
+          </div>
+          <CallingNotificationButton {...props} />
+        </div>
+      )}
+    </Measure>
+  );
+});
+
+function CallingNotificationButton(props: PropsType) {
+  if (props.callMode !== CallMode.Group || props.ended) {
     return null;
   }
-  const { acceptedTime, endedTime, wasVideoCall } = callHistoryDetails;
-  const callType = wasVideoCall ? 'video' : 'audio';
-  return (
-    <div
-      className={`module-message-calling--notification module-message-calling--${callType}`}
+
+  const {
+    activeCallConversationId,
+    conversationId,
+    deviceCount,
+    i18n,
+    maxDevices,
+    returnToActiveCall,
+    startCallingLobby,
+  } = props;
+
+  let buttonText: string;
+  let disabledTooltipText: undefined | string;
+  let onClick: undefined | (() => void);
+  if (activeCallConversationId) {
+    if (activeCallConversationId === conversationId) {
+      buttonText = i18n('calling__return');
+      onClick = returnToActiveCall;
+    } else {
+      buttonText = i18n('calling__join');
+      disabledTooltipText = i18n(
+        'calling__call-notification__button__in-another-call-tooltip'
+      );
+    }
+  } else if (deviceCount >= maxDevices) {
+    buttonText = i18n('calling__call-is-full');
+    disabledTooltipText = i18n(
+      'calling__call-notification__button__call-full-tooltip',
+      [String(deviceCount)]
+    );
+  } else {
+    buttonText = i18n('calling__join');
+    onClick = () => {
+      startCallingLobby({ conversationId, isVideoCall: true });
+    };
+  }
+
+  const button = (
+    <button
+      className="module-message-calling--notification__button"
+      disabled={Boolean(disabledTooltipText)}
+      onClick={onClick}
+      type="button"
     >
-      <div className={`module-message-calling--${callType}__icon`} />
-      {getCallingNotificationText(callHistoryDetails, i18n)}
-      <div>
-        <Timestamp
-          i18n={i18n}
-          timestamp={acceptedTime || endedTime}
-          extended
-          direction="outgoing"
-          withImageNoCaption={false}
-          withSticker={false}
-          withTapToViewExpired={false}
-          module="module-message__metadata__date"
-        />
-      </div>
-    </div>
+      {buttonText}
+    </button>
   );
-};
+
+  if (disabledTooltipText) {
+    return (
+      <Tooltip content={disabledTooltipText} direction={TooltipPlacement.Top}>
+        {button}
+      </Tooltip>
+    );
+  }
+  return button;
+}
diff --git a/ts/components/conversation/Timeline.stories.tsx b/ts/components/conversation/Timeline.stories.tsx
index 5cbeadf3e212..ef3c65d4d80c 100644
--- a/ts/components/conversation/Timeline.stories.tsx
+++ b/ts/components/conversation/Timeline.stories.tsx
@@ -247,6 +247,10 @@ const actions = () => ({
   showIdentity: action('showIdentity'),
 
   downloadNewVersion: action('downloadNewVersion'),
+
+  messageSizeChanged: action('messageSizeChanged'),
+  startCallingLobby: action('startCallingLobby'),
+  returnToActiveCall: action('returnToActiveCall'),
 });
 
 const renderItem = (id: string) => (
diff --git a/ts/components/conversation/TimelineItem.stories.tsx b/ts/components/conversation/TimelineItem.stories.tsx
index e74b32bd4977..072a4e2967a0 100644
--- a/ts/components/conversation/TimelineItem.stories.tsx
+++ b/ts/components/conversation/TimelineItem.stories.tsx
@@ -10,6 +10,7 @@ import { EmojiPicker } from '../emoji/EmojiPicker';
 import { setup as setupI18n } from '../../../js/modules/i18n';
 import enMessages from '../../../_locales/en/messages.json';
 import { PropsType as TimelineItemProps, TimelineItem } from './TimelineItem';
+import { CallMode } from '../../types/Calling';
 
 const i18n = setupI18n('en', enMessages);
 
@@ -61,6 +62,9 @@ const getDefaultProps = () => ({
   scrollToQuotedMessage: action('scrollToQuotedMessage'),
   downloadNewVersion: action('downloadNewVersion'),
   showIdentity: action('showIdentity'),
+  messageSizeChanged: action('messageSizeChanged'),
+  startCallingLobby: action('startCallingLobby'),
+  returnToActiveCall: action('returnToActiveCall'),
 
   renderContact,
   renderEmojiPicker,
@@ -95,149 +99,253 @@ storiesOf('Components/Conversation/TimelineItem', module)
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // declined incoming audio
-            wasDeclined: true,
-            wasIncoming: true,
-            wasVideoCall: false,
-            endedTime: Date.now(),
-          },
+          // declined incoming audio
+          callMode: CallMode.Direct,
+          wasDeclined: true,
+          wasIncoming: true,
+          wasVideoCall: false,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // declined incoming video
-            wasDeclined: true,
-            wasIncoming: true,
-            wasVideoCall: true,
-            endedTime: Date.now(),
-          },
+          // declined incoming video
+          callMode: CallMode.Direct,
+          wasDeclined: true,
+          wasIncoming: true,
+          wasVideoCall: true,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // accepted incoming audio
-            acceptedTime: Date.now() - 300,
-            wasDeclined: false,
-            wasIncoming: true,
-            wasVideoCall: false,
-            endedTime: Date.now(),
-          },
+          // accepted incoming audio
+          callMode: CallMode.Direct,
+          acceptedTime: Date.now() - 300,
+          wasDeclined: false,
+          wasIncoming: true,
+          wasVideoCall: false,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // accepted incoming video
-            acceptedTime: Date.now() - 400,
-            wasDeclined: false,
-            wasIncoming: true,
-            wasVideoCall: true,
-            endedTime: Date.now(),
-          },
+          // accepted incoming video
+          callMode: CallMode.Direct,
+          acceptedTime: Date.now() - 400,
+          wasDeclined: false,
+          wasIncoming: true,
+          wasVideoCall: true,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // missed (neither accepted nor declined) incoming audio
-            wasDeclined: false,
-            wasIncoming: true,
-            wasVideoCall: false,
-            endedTime: Date.now(),
-          },
+          // missed (neither accepted nor declined) incoming audio
+          callMode: CallMode.Direct,
+          wasDeclined: false,
+          wasIncoming: true,
+          wasVideoCall: false,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // missed (neither accepted nor declined) incoming video
-            wasDeclined: false,
-            wasIncoming: true,
-            wasVideoCall: true,
-            endedTime: Date.now(),
-          },
+          // missed (neither accepted nor declined) incoming video
+          callMode: CallMode.Direct,
+          wasDeclined: false,
+          wasIncoming: true,
+          wasVideoCall: true,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // accepted outgoing audio
-            acceptedTime: Date.now() - 200,
-            wasDeclined: false,
-            wasIncoming: false,
-            wasVideoCall: false,
-            endedTime: Date.now(),
-          },
+          // accepted outgoing audio
+          callMode: CallMode.Direct,
+          acceptedTime: Date.now() - 200,
+          wasDeclined: false,
+          wasIncoming: false,
+          wasVideoCall: false,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // accepted outgoing video
-            acceptedTime: Date.now() - 200,
-            wasDeclined: false,
-            wasIncoming: false,
-            wasVideoCall: true,
-            endedTime: Date.now(),
-          },
+          // accepted outgoing video
+          callMode: CallMode.Direct,
+          acceptedTime: Date.now() - 200,
+          wasDeclined: false,
+          wasIncoming: false,
+          wasVideoCall: true,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // declined outgoing audio
-            wasDeclined: true,
-            wasIncoming: false,
-            wasVideoCall: false,
-            endedTime: Date.now(),
-          },
+          // declined outgoing audio
+          callMode: CallMode.Direct,
+          wasDeclined: true,
+          wasIncoming: false,
+          wasVideoCall: false,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // declined outgoing video
-            wasDeclined: true,
-            wasIncoming: false,
-            wasVideoCall: true,
-            endedTime: Date.now(),
-          },
+          // declined outgoing video
+          callMode: CallMode.Direct,
+          wasDeclined: true,
+          wasIncoming: false,
+          wasVideoCall: true,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // missed (neither accepted nor declined) outgoing audio
-            wasDeclined: false,
-            wasIncoming: false,
-            wasVideoCall: false,
-            endedTime: Date.now(),
-          },
+          // missed (neither accepted nor declined) outgoing audio
+          callMode: CallMode.Direct,
+          wasDeclined: false,
+          wasIncoming: false,
+          wasVideoCall: false,
+          endedTime: Date.now(),
         },
       },
       {
         type: 'callHistory',
         data: {
-          callHistoryDetails: {
-            // missed (neither accepted nor declined) outgoing video
-            wasDeclined: false,
-            wasIncoming: false,
-            wasVideoCall: true,
-            endedTime: Date.now(),
+          // missed (neither accepted nor declined) outgoing video
+          callMode: CallMode.Direct,
+          wasDeclined: false,
+          wasIncoming: false,
+          wasVideoCall: true,
+          endedTime: Date.now(),
+        },
+      },
+      {
+        type: 'callHistory',
+        data: {
+          // ongoing group call
+          callMode: CallMode.Group,
+          conversationId: 'abc123',
+          creator: {
+            firstName: 'Luigi',
+            isMe: false,
+            title: 'Luigi Mario',
           },
+          ended: false,
+          deviceCount: 1,
+          maxDevices: 16,
+          startedTime: Date.now(),
+        },
+      },
+      {
+        type: 'callHistory',
+        data: {
+          // ongoing group call started by you
+          callMode: CallMode.Group,
+          conversationId: 'abc123',
+          creator: {
+            firstName: 'Peach',
+            isMe: true,
+            title: 'Princess Peach',
+          },
+          ended: false,
+          deviceCount: 1,
+          maxDevices: 16,
+          startedTime: Date.now(),
+        },
+      },
+      {
+        type: 'callHistory',
+        data: {
+          // ongoing group call, creator unknown
+          callMode: CallMode.Group,
+          conversationId: 'abc123',
+          ended: false,
+          deviceCount: 1,
+          maxDevices: 16,
+          startedTime: Date.now(),
+        },
+      },
+      {
+        type: 'callHistory',
+        data: {
+          // ongoing and active group call
+          callMode: CallMode.Group,
+          activeCallConversationId: 'abc123',
+          conversationId: 'abc123',
+          creator: {
+            firstName: 'Luigi',
+            isMe: false,
+            title: 'Luigi Mario',
+          },
+          ended: false,
+          deviceCount: 1,
+          maxDevices: 16,
+          startedTime: Date.now(),
+        },
+      },
+      {
+        type: 'callHistory',
+        data: {
+          // ongoing group call, but you're in another one
+          callMode: CallMode.Group,
+          activeCallConversationId: 'abc123',
+          conversationId: 'xyz987',
+          creator: {
+            firstName: 'Luigi',
+            isMe: false,
+            title: 'Luigi Mario',
+          },
+          ended: false,
+          deviceCount: 1,
+          maxDevices: 16,
+          startedTime: Date.now(),
+        },
+      },
+      {
+        type: 'callHistory',
+        data: {
+          // ongoing full group call
+          callMode: CallMode.Group,
+          conversationId: 'abc123',
+          creator: {
+            firstName: 'Luigi',
+            isMe: false,
+            title: 'Luigi Mario',
+          },
+          ended: false,
+          deviceCount: 16,
+          maxDevices: 16,
+          startedTime: Date.now(),
+        },
+      },
+      {
+        type: 'callHistory',
+        data: {
+          // finished call
+          callMode: CallMode.Group,
+          conversationId: 'abc123',
+          creator: {
+            firstName: 'Luigi',
+            isMe: false,
+            title: 'Luigi Mario',
+          },
+          ended: true,
+          deviceCount: 0,
+          maxDevices: 16,
+          startedTime: Date.now(),
         },
       },
     ];
diff --git a/ts/components/conversation/TimelineItem.tsx b/ts/components/conversation/TimelineItem.tsx
index 0276cac6ba7e..c61725140860 100644
--- a/ts/components/conversation/TimelineItem.tsx
+++ b/ts/components/conversation/TimelineItem.tsx
@@ -13,8 +13,9 @@ import {
 
 import {
   CallingNotification,
-  PropsData as CallingNotificationProps,
+  PropsActionsType as CallingNotificationActionsType,
 } from './CallingNotification';
+import { CallingNotificationType } from '../../util/callingNotification';
 import { InlineNotificationWrapper } from './InlineNotificationWrapper';
 import {
   PropsActions as UnsupportedMessageActionsType,
@@ -55,7 +56,7 @@ import {
 
 type CallHistoryType = {
   type: 'callHistory';
-  data: CallingNotificationProps;
+  data: CallingNotificationType;
 };
 type LinkNotificationType = {
   type: 'linkNotification';
@@ -128,6 +129,7 @@ type PropsLocalType = {
 };
 
 type PropsActionsType = MessageActionsType &
+  CallingNotificationActionsType &
   UnsupportedMessageActionsType &
   SafetyNumberActionsType;
 
@@ -143,8 +145,11 @@ export class TimelineItem extends React.PureComponent<PropsType> {
       isSelected,
       item,
       i18n,
+      messageSizeChanged,
       renderContact,
+      returnToActiveCall,
       selectMessage,
+      startCallingLobby,
     } = this.props;
 
     if (!item) {
@@ -164,7 +169,17 @@ export class TimelineItem extends React.PureComponent<PropsType> {
         <UnsupportedMessage {...this.props} {...item.data} i18n={i18n} />
       );
     } else if (item.type === 'callHistory') {
-      notification = <CallingNotification i18n={i18n} {...item.data} />;
+      notification = (
+        <CallingNotification
+          conversationId={conversationId}
+          i18n={i18n}
+          messageId={id}
+          messageSizeChanged={messageSizeChanged}
+          returnToActiveCall={returnToActiveCall}
+          startCallingLobby={startCallingLobby}
+          {...item.data}
+        />
+      );
     } else if (item.type === 'linkNotification') {
       notification = (
         <div className="module-message-unsynced">
diff --git a/ts/model-types.d.ts b/ts/model-types.d.ts
index d80e8d025699..cdb151aa02c1 100644
--- a/ts/model-types.d.ts
+++ b/ts/model-types.d.ts
@@ -5,7 +5,7 @@ import * as Backbone from 'backbone';
 
 import { GroupV2ChangeType } from './groups';
 import { LocalizerType, BodyRangeType, BodyRangesType } from './types/Util';
-import { CallHistoryDetailsType } from './types/Calling';
+import { CallHistoryDetailsFromDiskType } from './types/Calling';
 import { ColorType } from './types/Colors';
 import {
   ConversationType,
@@ -59,7 +59,7 @@ export type GroupMigrationType = {
 export type MessageAttributesType = {
   bodyPending: boolean;
   bodyRanges: BodyRangesType;
-  callHistoryDetails: CallHistoryDetailsType;
+  callHistoryDetails: CallHistoryDetailsFromDiskType;
   changedId: string;
   dataMessage: ArrayBuffer | null;
   decrypted_at: number;
diff --git a/ts/models/conversations.ts b/ts/models/conversations.ts
index 7dfeedd40b87..a97b62ca4654 100644
--- a/ts/models/conversations.ts
+++ b/ts/models/conversations.ts
@@ -10,7 +10,7 @@ import {
   ConversationAttributesType,
   VerificationOptions,
 } from '../model-types.d';
-import { CallHistoryDetailsType } from '../types/Calling';
+import { CallMode, CallHistoryDetailsType } from '../types/Calling';
 import { CallbackResultType, GroupV2InfoType } from '../textsecure/SendMessage';
 import {
   ConversationType,
@@ -19,6 +19,7 @@ import {
 import { ColorType } from '../types/Colors';
 import { MessageModel } from './messages';
 import { isMuted } from '../util/isMuted';
+import { missingCaseError } from '../util/missingCaseError';
 import { sniffImageMimeType } from '../util/sniffImageMimeType';
 import { MIMEType, IMAGE_WEBP } from '../types/MIME';
 import {
@@ -128,6 +129,8 @@ export class ConversationModel extends window.Backbone.Model<
 
   intlCollator = new Intl.Collator();
 
+  private cachedLatestGroupCallEraId?: string;
+
   // eslint-disable-next-line class-methods-use-this
   defaults(): Partial<ConversationAttributesType> {
     return {
@@ -2047,14 +2050,36 @@ export class ConversationModel extends window.Backbone.Model<
   async addCallHistory(
     callHistoryDetails: CallHistoryDetailsType
   ): Promise<void> {
-    const { acceptedTime, endedTime, wasDeclined } = callHistoryDetails;
+    let timestamp: number;
+    let unread: boolean;
+    let detailsToSave: CallHistoryDetailsType;
+
+    switch (callHistoryDetails.callMode) {
+      case CallMode.Direct:
+        timestamp = callHistoryDetails.endedTime;
+        unread =
+          !callHistoryDetails.wasDeclined && !callHistoryDetails.acceptedTime;
+        detailsToSave = {
+          ...callHistoryDetails,
+          callMode: CallMode.Direct,
+        };
+        break;
+      case CallMode.Group:
+        timestamp = callHistoryDetails.startedTime;
+        unread = false;
+        detailsToSave = callHistoryDetails;
+        break;
+      default:
+        throw missingCaseError(callHistoryDetails);
+    }
+
     const message = ({
       conversationId: this.id,
       type: 'call-history',
-      sent_at: endedTime,
-      received_at: endedTime,
-      unread: !wasDeclined && !acceptedTime,
-      callHistoryDetails,
+      sent_at: timestamp,
+      received_at: timestamp,
+      unread,
+      callHistoryDetails: detailsToSave,
       // TODO: DESKTOP-722
     } as unknown) as typeof window.Whisper.MessageAttributesType;
 
@@ -2072,6 +2097,27 @@ export class ConversationModel extends window.Backbone.Model<
     this.trigger('newmessage', model);
   }
 
+  async updateCallHistoryForGroupCall(
+    eraId: string,
+    creatorUuid: string
+  ): Promise<void> {
+    const alreadyHasMessage =
+      (this.cachedLatestGroupCallEraId &&
+        this.cachedLatestGroupCallEraId === eraId) ||
+      (await window.Signal.Data.hasGroupCallHistoryMessage(this.id, eraId));
+
+    if (!alreadyHasMessage) {
+      this.addCallHistory({
+        callMode: CallMode.Group,
+        creatorUuid,
+        eraId,
+        startedTime: Date.now(),
+      });
+    }
+
+    this.cachedLatestGroupCallEraId = eraId;
+  }
+
   async addProfileChange(
     profileChange: unknown,
     conversationId?: string
diff --git a/ts/models/messages.ts b/ts/models/messages.ts
index a584fca51ca9..fbb13027cd81 100644
--- a/ts/models/messages.ts
+++ b/ts/models/messages.ts
@@ -12,9 +12,13 @@ import {
   LastMessageStatus,
   ConversationType,
 } from '../state/ducks/conversations';
+import { getActiveCall } from '../state/ducks/calling';
+import { getCallSelector } from '../state/selectors/calling';
 import { PropsData } from '../components/conversation/Message';
 import { CallbackResultType } from '../textsecure/SendMessage';
 import { ExpirationTimerOptions } from '../util/ExpirationTimerOptions';
+import { missingCaseError } from '../util/missingCaseError';
+import { CallMode } from '../types/Calling';
 import { BodyRangesType } from '../types/Util';
 import { PropsDataType as GroupsV2Props } from '../components/conversation/GroupV2Change';
 import {
@@ -29,7 +33,10 @@ import {
   ChangeType,
 } from '../components/conversation/GroupNotification';
 import { Props as ResetSessionNotificationProps } from '../components/conversation/ResetSessionNotification';
-import { PropsData as CallingNotificationProps } from '../components/conversation/CallingNotification';
+import {
+  CallingNotificationType,
+  getCallingNotificationText,
+} from '../util/callingNotification';
 import { PropsType as ProfileChangeNotificationPropsType } from '../components/conversation/ProfileChangeNotification';
 
 /* eslint-disable camelcase */
@@ -704,10 +711,67 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
     };
   }
 
-  getPropsForCallHistory(): CallingNotificationProps {
-    return {
-      callHistoryDetails: this.get('callHistoryDetails'),
-    };
+  getPropsForCallHistory(): CallingNotificationType | undefined {
+    const callHistoryDetails = this.get('callHistoryDetails');
+    if (!callHistoryDetails) {
+      return undefined;
+    }
+
+    switch (callHistoryDetails.callMode) {
+      // Old messages weren't saved with a call mode.
+      case undefined:
+      case CallMode.Direct:
+        return {
+          ...callHistoryDetails,
+          callMode: CallMode.Direct,
+        };
+      case CallMode.Group: {
+        const conversationId = this.get('conversationId');
+        if (!conversationId) {
+          window.log.error(
+            'Message.prototype.getPropsForCallHistory: missing conversation ID; assuming there is no call'
+          );
+          return undefined;
+        }
+
+        const creatorConversation = this.findContact(
+          window.ConversationController.ensureContactIds({
+            uuid: callHistoryDetails.creatorUuid,
+          })
+        );
+        if (!creatorConversation) {
+          window.log.error(
+            'Message.prototype.getPropsForCallHistory: could not find creator by UUID; bailing'
+          );
+          return undefined;
+        }
+
+        const reduxState = window.reduxStore.getState();
+
+        let call = getCallSelector(reduxState)(conversationId);
+        if (call && call.callMode !== CallMode.Group) {
+          window.log.error(
+            'Message.prototype.getPropsForCallHistory: there is an unexpected non-group call; pretending it does not exist'
+          );
+          call = undefined;
+        }
+
+        return {
+          activeCallConversationId: getActiveCall(reduxState.calling)
+            ?.conversationId,
+          callMode: CallMode.Group,
+          conversationId,
+          creator: creatorConversation.format(),
+          deviceCount: call?.peekInfo.deviceCount ?? 0,
+          ended: callHistoryDetails.eraId !== call?.peekInfo.eraId,
+          maxDevices: call?.peekInfo.maxDevices ?? Infinity,
+          startedTime: callHistoryDetails.startedTime,
+        };
+      }
+      default:
+        window.log.error(missingCaseError(callHistoryDetails));
+        return undefined;
+    }
   }
 
   getPropsForProfileChange(): ProfileChangeNotificationPropsType {
@@ -1345,12 +1409,16 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
     }
 
     if (this.isCallHistory()) {
-      return {
-        text: window.Signal.Components.getCallingNotificationText(
-          this.get('callHistoryDetails'),
-          window.i18n
-        ),
-      };
+      const callingNotification = this.getPropsForCallHistory();
+      if (callingNotification) {
+        return {
+          text: getCallingNotificationText(callingNotification, window.i18n),
+        };
+      }
+
+      window.log.error(
+        "This call history message doesn't have valid call history"
+      );
     }
     if (this.isExpirationTimerUpdate()) {
       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
diff --git a/ts/services/calling.ts b/ts/services/calling.ts
index 3ff9f68bc2a5..b9bed598a254 100644
--- a/ts/services/calling.ts
+++ b/ts/services/calling.ts
@@ -124,11 +124,17 @@ export class CallingClass {
   }
 
   async startCallingLobby(
-    conversation: ConversationModel,
+    conversationId: string,
     isVideoCall: boolean
   ): Promise<void> {
     window.log.info('CallingClass.startCallingLobby()');
 
+    const conversation = window.ConversationController.get(conversationId);
+    if (!conversation) {
+      window.log.error('Could not find conversation, cannot start call lobby');
+      return;
+    }
+
     const conversationProps = conversation.format();
     const callMode = getConversationCallMode(conversationProps);
     switch (callMode) {
@@ -450,6 +456,10 @@ export class CallingClass {
         this.syncGroupCallToRedux(conversationId, groupCall);
       },
       onPeekChanged: groupCall => {
+        this.updateCallHistoryForGroupCall(
+          conversationId,
+          groupCall.getPeekInfo()
+        );
         this.syncGroupCallToRedux(conversationId, groupCall);
       },
       async requestMembershipProof(groupCall) {
@@ -1459,6 +1469,7 @@ export class CallingClass {
     }
 
     conversation.addCallHistory({
+      callMode: CallMode.Direct,
       wasIncoming: call.isIncoming,
       wasVideoCall: call.isVideoCall,
       wasDeclined,
@@ -1472,6 +1483,7 @@ export class CallingClass {
     wasVideoCall: boolean
   ) {
     conversation.addCallHistory({
+      callMode: CallMode.Direct,
       wasIncoming: true,
       wasVideoCall,
       // Since the user didn't decline, make sure it shows up as a missed call instead
@@ -1486,6 +1498,7 @@ export class CallingClass {
     _reason: CallEndedReason
   ) {
     conversation.addCallHistory({
+      callMode: CallMode.Direct,
       wasIncoming: true,
       // We don't actually know, but it doesn't seem that important in this case,
       // but we could maybe plumb this info through RingRTC
@@ -1496,6 +1509,31 @@ export class CallingClass {
       endedTime: Date.now(),
     });
   }
+
+  public updateCallHistoryForGroupCall(
+    conversationId: string,
+    peekInfo: undefined | PeekInfo
+  ): void {
+    // If we don't have the necessary pieces to peek, bail. (It's okay if we don't.)
+    if (!peekInfo || !peekInfo.eraId || !peekInfo.creator) {
+      return;
+    }
+    const creatorUuid = arrayBufferToUuid(peekInfo.creator);
+    if (!creatorUuid) {
+      window.log.error('updateCallHistoryForGroupCall(): bad creator UUID');
+      return;
+    }
+
+    const conversation = window.ConversationController.get(conversationId);
+    if (!conversation) {
+      window.log.error(
+        'updateCallHistoryForGroupCall(): could not find conversation'
+      );
+      return;
+    }
+
+    conversation.updateCallHistoryForGroupCall(peekInfo.eraId, creatorUuid);
+  }
 }
 
 export const calling = new CallingClass();
diff --git a/ts/sql/Client.ts b/ts/sql/Client.ts
index 44afcdacfdb7..ccba561aa22a 100644
--- a/ts/sql/Client.ts
+++ b/ts/sql/Client.ts
@@ -166,6 +166,7 @@ const dataInterface: ClientInterface = {
   getLastConversationActivity,
   getLastConversationPreview,
   getMessageMetricsForConversation,
+  hasGroupCallHistoryMessage,
   migrateConversationMessages,
 
   getUnprocessedCount,
@@ -1056,6 +1057,12 @@ async function getMessageMetricsForConversation(conversationId: string) {
 
   return result;
 }
+function hasGroupCallHistoryMessage(
+  conversationId: string,
+  eraId: string
+): Promise<boolean> {
+  return channels.hasGroupCallHistoryMessage(conversationId, eraId);
+}
 async function migrateConversationMessages(
   obsoleteId: string,
   currentId: string
diff --git a/ts/sql/Interface.ts b/ts/sql/Interface.ts
index 3ff01e34e6fd..7a1bf1fcffbf 100644
--- a/ts/sql/Interface.ts
+++ b/ts/sql/Interface.ts
@@ -103,6 +103,10 @@ export interface DataInterface {
   getMessageMetricsForConversation: (
     conversationId: string
   ) => Promise<ConverationMetricsType>;
+  hasGroupCallHistoryMessage: (
+    conversationId: string,
+    eraId: string
+  ) => Promise<boolean>;
   migrateConversationMessages: (
     obsoleteId: string,
     currentId: string
diff --git a/ts/sql/Server.ts b/ts/sql/Server.ts
index 9d5bb1bfbfd5..104c4dd98403 100644
--- a/ts/sql/Server.ts
+++ b/ts/sql/Server.ts
@@ -145,6 +145,7 @@ const dataInterface: ServerInterface = {
   getMessageMetricsForConversation,
   getLastConversationActivity,
   getLastConversationPreview,
+  hasGroupCallHistoryMessage,
   migrateConversationMessages,
 
   getUnprocessedCount,
@@ -2880,6 +2881,34 @@ async function getMessageMetricsForConversation(conversationId: string) {
 }
 getMessageMetricsForConversation.needsSerial = true;
 
+async function hasGroupCallHistoryMessage(
+  conversationId: string,
+  eraId: string
+): Promise<boolean> {
+  const db = getInstance();
+
+  const row: unknown = await db.get(
+    `
+    SELECT count(*) FROM messages
+    WHERE conversationId = $conversationId
+    AND type = 'call-history'
+    AND json_extract(json, '$.callHistoryDetails.callMode') = 'Group'
+    AND json_extract(json, '$.callHistoryDetails.eraId') = $eraId
+    LIMIT 1;
+    `,
+    {
+      $conversationId: conversationId,
+      $eraId: eraId,
+    }
+  );
+
+  if (typeof row === 'object' && row && !Array.isArray(row)) {
+    const count = Number((row as Record<string, unknown>)['count(*)']);
+    return Boolean(count);
+  }
+  return false;
+}
+
 async function migrateConversationMessages(
   obsoleteId: string,
   currentId: string
diff --git a/ts/state/ducks/calling.ts b/ts/state/ducks/calling.ts
index 6baad1f2abc6..81c782959e11 100644
--- a/ts/state/ducks/calling.ts
+++ b/ts/state/ducks/calling.ts
@@ -163,6 +163,11 @@ export type SetGroupCallVideoRequestType = {
   resolutions: Array<GroupCallVideoRequest>;
 };
 
+export type StartCallingLobbyType = {
+  conversationId: string;
+  isVideoCall: boolean;
+};
+
 export type ShowCallLobbyType =
   | {
       callMode: CallMode.Direct;
@@ -220,6 +225,7 @@ const PEEK_NOT_CONNECTED_GROUP_CALL_FULFILLED =
   'calling/PEEK_NOT_CONNECTED_GROUP_CALL_FULFILLED';
 const REFRESH_IO_DEVICES = 'calling/REFRESH_IO_DEVICES';
 const REMOTE_VIDEO_CHANGE = 'calling/REMOTE_VIDEO_CHANGE';
+const RETURN_TO_ACTIVE_CALL = 'calling/RETURN_TO_ACTIVE_CALL';
 const SET_LOCAL_AUDIO_FULFILLED = 'calling/SET_LOCAL_AUDIO_FULFILLED';
 const SET_LOCAL_VIDEO_FULFILLED = 'calling/SET_LOCAL_VIDEO_FULFILLED';
 const START_DIRECT_CALL = 'calling/START_DIRECT_CALL';
@@ -281,7 +287,7 @@ type OutgoingCallActionType = {
   payload: StartDirectCallType;
 };
 
-type PeekNotConnectedGroupCallFulfilledActionType = {
+export type PeekNotConnectedGroupCallFulfilledActionType = {
   type: 'calling/PEEK_NOT_CONNECTED_GROUP_CALL_FULFILLED';
   payload: {
     conversationId: string;
@@ -300,6 +306,10 @@ type RemoteVideoChangeActionType = {
   payload: RemoteVideoChangeType;
 };
 
+type ReturnToActiveCallActionType = {
+  type: 'calling/RETURN_TO_ACTIVE_CALL';
+};
+
 type SetLocalAudioActionType = {
   type: 'calling/SET_LOCAL_AUDIO_FULFILLED';
   payload: SetLocalAudioType;
@@ -347,6 +357,7 @@ export type CallingActionType =
   | PeekNotConnectedGroupCallFulfilledActionType
   | RefreshIODevicesActionType
   | RemoteVideoChangeActionType
+  | ReturnToActiveCallActionType
   | SetLocalAudioActionType
   | SetLocalVideoFulfilledActionType
   | ShowCallLobbyActionType
@@ -577,6 +588,8 @@ function peekNotConnectedGroupCall(
         return;
       }
 
+      calling.updateCallHistoryForGroupCall(conversationId, peekInfo);
+
       dispatch({
         type: PEEK_NOT_CONNECTED_GROUP_CALL_FULFILLED,
         payload: {
@@ -607,6 +620,12 @@ function remoteVideoChange(
   };
 }
 
+function returnToActiveCall(): ReturnToActiveCallActionType {
+  return {
+    type: RETURN_TO_ACTIVE_CALL,
+  };
+}
+
 function setLocalPreview(
   payload: SetLocalPreviewType
 ): ThunkAction<void, RootStateType, unknown, never> {
@@ -695,6 +714,16 @@ function setGroupCallVideoRequest(
   };
 }
 
+function startCallingLobby(
+  payload: StartCallingLobbyType
+): ThunkAction<void, RootStateType, unknown, never> {
+  return () => {
+    calling.startCallingLobby(payload.conversationId, payload.isVideoCall);
+  };
+}
+
+// TODO: This action should be replaced with an action dispatched in the
+//   `startCallingLobby` thunk.
 function showCallLobby(payload: ShowCallLobbyType): CallLobbyActionType {
   return {
     type: SHOW_CALL_LOBBY,
@@ -765,11 +794,13 @@ export const actions = {
   peekNotConnectedGroupCall,
   refreshIODevices,
   remoteVideoChange,
+  returnToActiveCall,
   setLocalPreview,
   setRendererCanvas,
   setLocalAudio,
   setLocalVideo,
   setGroupCallVideoRequest,
+  startCallingLobby,
   showCallLobby,
   startCall,
   toggleParticipants,
@@ -1159,6 +1190,24 @@ export function reducer(
     };
   }
 
+  if (action.type === RETURN_TO_ACTIVE_CALL) {
+    const { activeCallState } = state;
+    if (!activeCallState) {
+      window.log.warn(
+        'Cannot return to active call if there is no active call'
+      );
+      return state;
+    }
+
+    return {
+      ...state,
+      activeCallState: {
+        ...activeCallState,
+        pip: false,
+      },
+    };
+  }
+
   if (action.type === SET_LOCAL_AUDIO_FULFILLED) {
     if (!state.activeCallState) {
       window.log.warn('Cannot set local audio with no active call');
diff --git a/ts/state/ducks/conversations.ts b/ts/state/ducks/conversations.ts
index 959f287c24ce..a74ea5c5aaa3 100644
--- a/ts/state/ducks/conversations.ts
+++ b/ts/state/ducks/conversations.ts
@@ -20,7 +20,7 @@ import { NoopActionType } from './noop';
 import { AttachmentType } from '../../types/Attachment';
 import { ColorType } from '../../types/Colors';
 import { BodyRangeType } from '../../types/Util';
-import { CallMode } from '../../types/Calling';
+import { CallMode, CallHistoryDetailsFromDiskType } from '../../types/Calling';
 
 // State
 
@@ -147,6 +147,7 @@ export type MessageType = {
 
   errors?: Array<Error>;
   group_update?: unknown;
+  callHistoryDetails?: CallHistoryDetailsFromDiskType;
 
   // No need to go beyond this; unused at this stage, since this goes into
   //   a reducer still in plain JavaScript and comes out well-formed
@@ -274,6 +275,13 @@ export type MessageDeletedActionType = {
     conversationId: string;
   };
 };
+type MessageSizeChangedActionType = {
+  type: 'MESSAGE_SIZE_CHANGED';
+  payload: {
+    id: string;
+    conversationId: string;
+  };
+};
 export type MessagesAddedActionType = {
   type: 'MESSAGES_ADDED';
   payload: {
@@ -379,6 +387,7 @@ export type ConversationActionType =
   | ConversationUnloadedActionType
   | RemoveAllConversationsActionType
   | MessageSelectedActionType
+  | MessageSizeChangedActionType
   | MessageChangedActionType
   | MessageDeletedActionType
   | MessagesAddedActionType
@@ -410,6 +419,7 @@ export const actions = {
   selectMessage,
   messageDeleted,
   messageChanged,
+  messageSizeChanged,
   messagesAdded,
   messagesReset,
   setMessagesLoading,
@@ -514,6 +524,18 @@ function messageDeleted(
     },
   };
 }
+function messageSizeChanged(
+  id: string,
+  conversationId: string
+): MessageSizeChangedActionType {
+  return {
+    type: 'MESSAGE_SIZE_CHANGED',
+    payload: {
+      id,
+      conversationId,
+    },
+  };
+}
 function messagesAdded(
   conversationId: string,
   messages: Array<MessageType>,
@@ -697,7 +719,7 @@ function showArchivedConversations(): ShowArchivedConversationsActionType {
 
 // Reducer
 
-function getEmptyState(): ConversationsStateType {
+export function getEmptyState(): ConversationsStateType {
   return {
     conversationLookup: {},
     messagesByConversation: {},
@@ -926,6 +948,31 @@ export function reducer(
       },
     };
   }
+  if (action.type === 'MESSAGE_SIZE_CHANGED') {
+    const { id, conversationId } = action.payload;
+
+    const existingConversation = getOwn(
+      state.messagesByConversation,
+      conversationId
+    );
+    if (!existingConversation) {
+      return state;
+    }
+
+    return {
+      ...state,
+      messagesByConversation: {
+        ...state.messagesByConversation,
+        [conversationId]: {
+          ...existingConversation,
+          heightChangeMessageIds: uniq([
+            ...existingConversation.heightChangeMessageIds,
+            id,
+          ]),
+        },
+      },
+    };
+  }
   if (action.type === 'MESSAGES_RESET') {
     const {
       conversationId,
diff --git a/ts/state/selectors/calling.ts b/ts/state/selectors/calling.ts
index 5f065399aac7..8ddbbb501dbe 100644
--- a/ts/state/selectors/calling.ts
+++ b/ts/state/selectors/calling.ts
@@ -10,15 +10,22 @@ import {
   DirectCallStateType,
 } from '../ducks/calling';
 import { CallMode, CallState } from '../../types/Calling';
+import { getOwn } from '../../util/getOwn';
 
 const getCalling = (state: StateType): CallingStateType => state.calling;
 
-const getCallsByConversation = createSelector(
+export const getCallsByConversation = createSelector(
   getCalling,
   (state: CallingStateType): CallsByConversationType =>
     state.callsByConversation
 );
 
+export const getCallSelector = createSelector(
+  getCallsByConversation,
+  (callsByConversation: CallsByConversationType) => (conversationId: string) =>
+    getOwn(callsByConversation, conversationId)
+);
+
 // In theory, there could be multiple incoming calls. In practice, neither RingRTC nor the
 //   UI are ready to handle this.
 export const getIncomingCall = createSelector(
diff --git a/ts/state/selectors/conversations.ts b/ts/state/selectors/conversations.ts
index 612987b895b5..2c675db7ce7b 100644
--- a/ts/state/selectors/conversations.ts
+++ b/ts/state/selectors/conversations.ts
@@ -15,7 +15,8 @@ import {
   MessagesByConversationType,
   MessageType,
 } from '../ducks/conversations';
-
+import type { CallsByConversationType } from '../ducks/calling';
+import { getCallsByConversation } from './calling';
 import { getBubbleProps } from '../../shims/Whisper';
 import { PropsDataType as TimelinePropsType } from '../../components/conversation/Timeline';
 import { TimelineItemType } from '../../components/conversation/TimelineItem';
@@ -254,6 +255,7 @@ export function _messageSelector(
   _ourNumber: string,
   _regionCode: string,
   interactionMode: 'mouse' | 'keyboard',
+  _callsByConversation: CallsByConversationType,
   _conversation?: ConversationType,
   _author?: ConversationType,
   _quoted?: ConversationType,
@@ -292,6 +294,7 @@ type CachedMessageSelectorType = (
   ourNumber: string,
   regionCode: string,
   interactionMode: 'mouse' | 'keyboard',
+  callsByConversation: CallsByConversationType,
   conversation?: ConversationType,
   author?: ConversationType,
   quoted?: ConversationType,
@@ -317,6 +320,7 @@ export const getMessageSelector = createSelector(
   getRegionCode,
   getUserNumber,
   getInteractionMode,
+  getCallsByConversation,
   (
     messageSelector: CachedMessageSelectorType,
     messageLookup: MessageLookupType,
@@ -324,7 +328,8 @@ export const getMessageSelector = createSelector(
     conversationSelector: GetConversationByIdType,
     regionCode: string,
     ourNumber: string,
-    interactionMode: 'keyboard' | 'mouse'
+    interactionMode: 'keyboard' | 'mouse',
+    callsByConversation: CallsByConversationType
   ): GetMessageByIdType => {
     return (id: string) => {
       const message = messageLookup[id];
@@ -352,6 +357,7 @@ export const getMessageSelector = createSelector(
         ourNumber,
         regionCode,
         interactionMode,
+        callsByConversation,
         conversation,
         author,
         quoted,
diff --git a/ts/test-both/state/ducks/conversations_test.ts b/ts/test-both/state/ducks/conversations_test.ts
index d9d41482eff7..3a87303359a4 100644
--- a/ts/test-both/state/ducks/conversations_test.ts
+++ b/ts/test-both/state/ducks/conversations_test.ts
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import { assert } from 'chai';
+import { set } from 'lodash/fp';
 import {
   actions,
   ConversationMessageType,
@@ -13,7 +14,11 @@ import {
 } from '../../../state/ducks/conversations';
 import { CallMode } from '../../../types/Calling';
 
-const { repairNewestMessage, repairOldestMessage } = actions;
+const {
+  messageSizeChanged,
+  repairNewestMessage,
+  repairOldestMessage,
+} = actions;
 
 describe('both/state/ducks/conversations', () => {
   describe('helpers', () => {
@@ -167,6 +172,76 @@ describe('both/state/ducks/conversations', () => {
       };
     }
 
+    describe('MESSAGE_SIZE_CHANGED', () => {
+      const stateWithActiveConversation = {
+        ...getDefaultState(),
+        messagesByConversation: {
+          [conversationId]: {
+            heightChangeMessageIds: [],
+            isLoadingMessages: false,
+            isNearBottom: true,
+            messageIds: [messageId],
+            metrics: { totalUnread: 0 },
+            resetCounter: 0,
+            scrollToMessageCounter: 0,
+          },
+        },
+        messagesLookup: {
+          [messageId]: getDefaultMessage(messageId),
+        },
+      };
+
+      it('does nothing if no conversation is active', () => {
+        const state = getDefaultState();
+
+        assert.strictEqual(
+          reducer(state, messageSizeChanged('messageId', 'convoId')),
+          state
+        );
+      });
+
+      it('does nothing if a different conversation is active', () => {
+        assert.deepEqual(
+          reducer(
+            stateWithActiveConversation,
+            messageSizeChanged(messageId, 'another-conversation-guid')
+          ),
+          stateWithActiveConversation
+        );
+      });
+
+      it('adds the message ID to the list of messages with changed heights', () => {
+        const result = reducer(
+          stateWithActiveConversation,
+          messageSizeChanged(messageId, conversationId)
+        );
+
+        assert.sameMembers(
+          result.messagesByConversation[conversationId]
+            ?.heightChangeMessageIds || [],
+          [messageId]
+        );
+      });
+
+      it("doesn't add duplicates to the list of changed-heights messages", () => {
+        const state = set(
+          ['messagesByConversation', conversationId, 'heightChangeMessageIds'],
+          [messageId],
+          stateWithActiveConversation
+        );
+        const result = reducer(
+          state,
+          messageSizeChanged(messageId, conversationId)
+        );
+
+        assert.sameMembers(
+          result.messagesByConversation[conversationId]
+            ?.heightChangeMessageIds || [],
+          [messageId]
+        );
+      });
+    });
+
     describe('REPAIR_NEWEST_MESSAGE', () => {
       it('updates newest', () => {
         const action = repairNewestMessage(conversationId);
diff --git a/ts/test-both/util/callingNotification_test.ts b/ts/test-both/util/callingNotification_test.ts
new file mode 100644
index 000000000000..aebe9ba453ae
--- /dev/null
+++ b/ts/test-both/util/callingNotification_test.ts
@@ -0,0 +1,115 @@
+// Copyright 2020 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+import { getCallingNotificationText } from '../../util/callingNotification';
+import { CallMode } from '../../types/Calling';
+import { setup as setupI18n } from '../../../js/modules/i18n';
+import enMessages from '../../../_locales/en/messages.json';
+
+describe('calling notification helpers', () => {
+  const i18n = setupI18n('en', enMessages);
+
+  describe('getCallingNotificationText', () => {
+    // Direct call behavior is not tested here.
+
+    it('says that the call has ended', () => {
+      assert.strictEqual(
+        getCallingNotificationText(
+          {
+            callMode: CallMode.Group,
+            conversationId: 'abc123',
+            ended: true,
+            deviceCount: 1,
+            maxDevices: 23,
+            startedTime: Date.now(),
+          },
+          i18n
+        ),
+        'The group call has ended'
+      );
+    });
+
+    it("includes the creator's first name when describing a call", () => {
+      assert.strictEqual(
+        getCallingNotificationText(
+          {
+            callMode: CallMode.Group,
+            conversationId: 'abc123',
+            creator: {
+              firstName: 'Luigi',
+              isMe: false,
+              title: 'Luigi Mario',
+            },
+            ended: false,
+            deviceCount: 1,
+            maxDevices: 23,
+            startedTime: Date.now(),
+          },
+          i18n
+        ),
+        'Luigi started a group call'
+      );
+    });
+
+    it("if the creator doesn't have a first name, falls back to their title", () => {
+      assert.strictEqual(
+        getCallingNotificationText(
+          {
+            callMode: CallMode.Group,
+            conversationId: 'abc123',
+            creator: {
+              isMe: false,
+              title: 'Luigi Mario',
+            },
+            ended: false,
+            deviceCount: 1,
+            maxDevices: 23,
+            startedTime: Date.now(),
+          },
+          i18n
+        ),
+        'Luigi Mario started a group call'
+      );
+    });
+
+    it('has a special message if you were the one to start the call', () => {
+      assert.strictEqual(
+        getCallingNotificationText(
+          {
+            callMode: CallMode.Group,
+            conversationId: 'abc123',
+            creator: {
+              firstName: 'ShouldBeIgnored',
+              isMe: true,
+              title: 'ShouldBeIgnored Smith',
+            },
+            ended: false,
+            deviceCount: 1,
+            maxDevices: 23,
+            startedTime: Date.now(),
+          },
+          i18n
+        ),
+        'You started a group call'
+      );
+    });
+
+    it('handles an unknown creator', () => {
+      assert.strictEqual(
+        getCallingNotificationText(
+          {
+            callMode: CallMode.Group,
+            conversationId: 'abc123',
+            ended: false,
+            deviceCount: 1,
+            maxDevices: 23,
+            startedTime: Date.now(),
+          },
+          i18n
+        ),
+        'A group call was started'
+      );
+    });
+  });
+});
diff --git a/ts/test-electron/state/ducks/calling_test.ts b/ts/test-electron/state/ducks/calling_test.ts
index c01126f3c701..2613a43efa12 100644
--- a/ts/test-electron/state/ducks/calling_test.ts
+++ b/ts/test-electron/state/ducks/calling_test.ts
@@ -27,7 +27,7 @@ describe('calling duck', () => {
     ...getEmptyState(),
     callsByConversation: {
       'fake-direct-call-conversation-id': {
-        callMode: CallMode.Direct,
+        callMode: CallMode.Direct as CallMode.Direct,
         conversationId: 'fake-direct-call-conversation-id',
         callState: CallState.Accepted,
         isIncoming: false,
@@ -37,7 +37,7 @@ describe('calling duck', () => {
     },
   };
 
-  const stateWithActiveDirectCall: CallingStateType = {
+  const stateWithActiveDirectCall = {
     ...stateWithDirectCall,
     activeCallState: {
       conversationId: 'fake-direct-call-conversation-id',
@@ -49,11 +49,11 @@ describe('calling duck', () => {
     },
   };
 
-  const stateWithIncomingDirectCall: CallingStateType = {
+  const stateWithIncomingDirectCall = {
     ...getEmptyState(),
     callsByConversation: {
       'fake-direct-call-conversation-id': {
-        callMode: CallMode.Direct,
+        callMode: CallMode.Direct as CallMode.Direct,
         conversationId: 'fake-direct-call-conversation-id',
         callState: CallState.Ringing,
         isIncoming: true,
@@ -63,11 +63,11 @@ describe('calling duck', () => {
     },
   };
 
-  const stateWithGroupCall: CallingStateType = {
+  const stateWithGroupCall = {
     ...getEmptyState(),
     callsByConversation: {
       'fake-group-call-conversation-id': {
-        callMode: CallMode.Group,
+        callMode: CallMode.Group as CallMode.Group,
         conversationId: 'fake-group-call-conversation-id',
         connectionState: GroupCallConnectionState.Connected,
         joinState: GroupCallJoinState.NotJoined,
@@ -91,7 +91,7 @@ describe('calling duck', () => {
     },
   };
 
-  const stateWithActiveGroupCall: CallingStateType = {
+  const stateWithActiveGroupCall = {
     ...stateWithGroupCall,
     activeCallState: {
       conversationId: 'fake-group-call-conversation-id',
@@ -624,6 +624,10 @@ describe('calling duck', () => {
           callingService,
           'peekGroupCall'
         );
+        this.callingServiceUpdateCallHistoryForGroupCall = this.sandbox.stub(
+          callingService,
+          'updateCallHistoryForGroupCall'
+        );
         this.clock = this.sandbox.useFakeTimers();
       });
 
@@ -677,6 +681,29 @@ describe('calling duck', () => {
       });
     });
 
+    describe('returnToActiveCall', () => {
+      const { returnToActiveCall } = actions;
+
+      it('does nothing if not in PiP mode', () => {
+        const result = reducer(stateWithActiveDirectCall, returnToActiveCall());
+
+        assert.deepEqual(result, stateWithActiveDirectCall);
+      });
+
+      it('closes the PiP', () => {
+        const state = {
+          ...stateWithActiveDirectCall,
+          activeCallState: {
+            ...stateWithActiveDirectCall.activeCallState,
+            pip: true,
+          },
+        };
+        const result = reducer(state, returnToActiveCall());
+
+        assert.deepEqual(result, stateWithActiveDirectCall);
+      });
+    });
+
     describe('setLocalAudio', () => {
       const { setLocalAudio } = actions;
 
diff --git a/ts/test-electron/state/selectors/calling_test.ts b/ts/test-electron/state/selectors/calling_test.ts
index 1748e8251386..2cdfc61700cf 100644
--- a/ts/test-electron/state/selectors/calling_test.ts
+++ b/ts/test-electron/state/selectors/calling_test.ts
@@ -5,7 +5,11 @@ import { assert } from 'chai';
 import { reducer as rootReducer } from '../../../state/reducer';
 import { noopAction } from '../../../state/ducks/noop';
 import { CallMode, CallState } from '../../../types/Calling';
-import { getIncomingCall } from '../../../state/selectors/calling';
+import {
+  getCallsByConversation,
+  getCallSelector,
+  getIncomingCall,
+} from '../../../state/selectors/calling';
 import { getEmptyState, CallingStateType } from '../../../state/ducks/calling';
 
 describe('state/selectors/calling', () => {
@@ -56,6 +60,50 @@ describe('state/selectors/calling', () => {
     },
   };
 
+  describe('getCallsByConversation', () => {
+    it('returns state.calling.callsByConversation', () => {
+      assert.deepEqual(getCallsByConversation(getEmptyRootState()), {});
+
+      assert.deepEqual(
+        getCallsByConversation(getCallingState(stateWithDirectCall)),
+        {
+          'fake-direct-call-conversation-id': {
+            callMode: CallMode.Direct,
+            conversationId: 'fake-direct-call-conversation-id',
+            callState: CallState.Accepted,
+            isIncoming: false,
+            isVideoCall: false,
+            hasRemoteVideo: false,
+          },
+        }
+      );
+    });
+  });
+
+  describe('getCallSelector', () => {
+    it('returns a selector that returns undefined if selecting a conversation with no call', () => {
+      assert.isUndefined(
+        getCallSelector(getEmptyRootState())('conversation-id')
+      );
+    });
+
+    it("returns a selector that returns a conversation's call", () => {
+      assert.deepEqual(
+        getCallSelector(getCallingState(stateWithDirectCall))(
+          'fake-direct-call-conversation-id'
+        ),
+        {
+          callMode: CallMode.Direct,
+          conversationId: 'fake-direct-call-conversation-id',
+          callState: CallState.Accepted,
+          isIncoming: false,
+          isVideoCall: false,
+          hasRemoteVideo: false,
+        }
+      );
+    });
+  });
+
   describe('getIncomingCall', () => {
     it('returns undefined if there are no calls', () => {
       assert.isUndefined(getIncomingCall(getEmptyRootState()));
diff --git a/ts/types/Calling.ts b/ts/types/Calling.ts
index f2ea6dbf8761..2f594bff2425 100644
--- a/ts/types/Calling.ts
+++ b/ts/types/Calling.ts
@@ -4,6 +4,7 @@
 import { ColorType } from './Colors';
 import { ConversationType } from '../state/ducks/conversations';
 
+// These are strings (1) for the database (2) for Storybook.
 export enum CallMode {
   None = 'None',
   Direct = 'Direct',
@@ -153,13 +154,31 @@ export type MediaDeviceSettings = {
   selectedCamera: string | undefined;
 };
 
-export type CallHistoryDetailsType = {
+interface DirectCallHistoryDetailsType {
+  callMode: CallMode.Direct;
   wasIncoming: boolean;
   wasVideoCall: boolean;
   wasDeclined: boolean;
   acceptedTime?: number;
   endedTime: number;
-};
+}
+
+interface GroupCallHistoryDetailsType {
+  callMode: CallMode.Group;
+  creatorUuid: string;
+  eraId: string;
+  startedTime: number;
+}
+
+export type CallHistoryDetailsType =
+  | DirectCallHistoryDetailsType
+  | GroupCallHistoryDetailsType;
+
+// Old messages weren't saved with a `callMode`.
+export type CallHistoryDetailsFromDiskType =
+  | (Omit<DirectCallHistoryDetailsType, 'callMode'> &
+      Partial<Pick<DirectCallHistoryDetailsType, 'callMode'>>)
+  | GroupCallHistoryDetailsType;
 
 export type ChangeIODevicePayloadType =
   | { type: CallingDeviceType.CAMERA; selectedDevice: string }
diff --git a/ts/util/callingNotification.ts b/ts/util/callingNotification.ts
new file mode 100644
index 000000000000..b302994bf4dd
--- /dev/null
+++ b/ts/util/callingNotification.ts
@@ -0,0 +1,108 @@
+// Copyright 2020 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { LocalizerType } from '../types/Util';
+import { CallMode } from '../types/Calling';
+import { missingCaseError } from './missingCaseError';
+
+interface DirectCallNotificationType {
+  callMode: CallMode.Direct;
+  wasIncoming: boolean;
+  wasVideoCall: boolean;
+  wasDeclined: boolean;
+  acceptedTime?: number;
+  endedTime: number;
+}
+
+interface GroupCallNotificationType {
+  activeCallConversationId?: string;
+  callMode: CallMode.Group;
+  conversationId: string;
+  creator?: {
+    firstName?: string;
+    isMe?: boolean;
+    title: string;
+  };
+  ended: boolean;
+  deviceCount: number;
+  maxDevices: number;
+  startedTime: number;
+}
+
+export type CallingNotificationType =
+  | DirectCallNotificationType
+  | GroupCallNotificationType;
+
+function getDirectCallNotificationText(
+  {
+    wasIncoming,
+    wasVideoCall,
+    wasDeclined,
+    acceptedTime,
+  }: DirectCallNotificationType,
+  i18n: LocalizerType
+): string {
+  const wasAccepted = Boolean(acceptedTime);
+
+  if (wasIncoming) {
+    if (wasDeclined) {
+      if (wasVideoCall) {
+        return i18n('declinedIncomingVideoCall');
+      }
+      return i18n('declinedIncomingAudioCall');
+    }
+    if (wasAccepted) {
+      if (wasVideoCall) {
+        return i18n('acceptedIncomingVideoCall');
+      }
+      return i18n('acceptedIncomingAudioCall');
+    }
+    if (wasVideoCall) {
+      return i18n('missedIncomingVideoCall');
+    }
+    return i18n('missedIncomingAudioCall');
+  }
+  if (wasAccepted) {
+    if (wasVideoCall) {
+      return i18n('acceptedOutgoingVideoCall');
+    }
+    return i18n('acceptedOutgoingAudioCall');
+  }
+  if (wasVideoCall) {
+    return i18n('missedOrDeclinedOutgoingVideoCall');
+  }
+  return i18n('missedOrDeclinedOutgoingAudioCall');
+}
+
+function getGroupCallNotificationText(
+  notification: GroupCallNotificationType,
+  i18n: LocalizerType
+): string {
+  if (notification.ended) {
+    return i18n('calling__call-notification__ended');
+  }
+  if (!notification.creator) {
+    return i18n('calling__call-notification__started-by-someone');
+  }
+  if (notification.creator.isMe) {
+    return i18n('calling__call-notification__started-by-you');
+  }
+  return i18n('calling__call-notification__started', [
+    notification.creator.firstName || notification.creator.title,
+  ]);
+}
+
+export function getCallingNotificationText(
+  notification: CallingNotificationType,
+  i18n: LocalizerType
+): string {
+  switch (notification.callMode) {
+    case CallMode.Direct:
+      return getDirectCallNotificationText(notification, i18n);
+    case CallMode.Group:
+      return getGroupCallNotificationText(notification, i18n);
+    default:
+      window.log.error(missingCaseError(notification));
+      return '';
+  }
+}
diff --git a/ts/util/lint/exceptions.json b/ts/util/lint/exceptions.json
index 6ee5df888800..6614e3f2e1d3 100644
--- a/ts/util/lint/exceptions.json
+++ b/ts/util/lint/exceptions.json
@@ -14699,6 +14699,24 @@
     "updated": "2020-10-26T19:12:24.410Z",
     "reasonDetail": "Only used to focus the element."
   },
+  {
+    "rule": "React-useRef",
+    "path": "ts/components/Tooltip.js",
+    "line": "    const wrapperRef = react_1.default.useRef(null);",
+    "lineNumber": 17,
+    "reasonCategory": "usageTrusted",
+    "updated": "2020-12-04T00:11:08.128Z",
+    "reasonDetail": "Used to add (and remove) event listeners."
+  },
+  {
+    "rule": "React-useRef",
+    "path": "ts/components/conversation/CallingNotification.js",
+    "line": "    const previousHeightRef = react_1.useRef(null);",
+    "lineNumber": 24,
+    "reasonCategory": "usageTrusted",
+    "updated": "2020-12-04T00:11:08.128Z",
+    "reasonDetail": "Doesn't interact with the DOM."
+  },
   {
     "rule": "React-useRef",
     "path": "ts/components/conversation/ContactModal.js",
@@ -15167,4 +15185,4 @@
     "reasonCategory": "falseMatch",
     "updated": "2020-09-08T23:07:22.682Z"
   }
-]
\ No newline at end of file
+]
diff --git a/ts/views/conversation_view.ts b/ts/views/conversation_view.ts
index e661f5bc858c..fad0a32ed314 100644
--- a/ts/views/conversation_view.ts
+++ b/ts/views/conversation_view.ts
@@ -478,7 +478,6 @@ Whisper.ConversationView = Whisper.View.extend({
               'onOutgoingAudioCallInConversation: about to start an audio call'
             );
 
-            const conversation = this.model;
             const isVideoCall = false;
 
             if (await this.isCallSafe()) {
@@ -486,7 +485,7 @@ Whisper.ConversationView = Whisper.View.extend({
                 'onOutgoingAudioCallInConversation: call is deemed "safe". Making call'
               );
               await window.Signal.Services.calling.startCallingLobby(
-                conversation,
+                this.model.id,
                 isVideoCall
               );
               window.log.info(
@@ -503,7 +502,6 @@ Whisper.ConversationView = Whisper.View.extend({
             window.log.info(
               'onOutgoingVideoCallInConversation: about to start a video call'
             );
-            const conversation = this.model;
             const isVideoCall = true;
 
             if (await this.isCallSafe()) {
@@ -511,7 +509,7 @@ Whisper.ConversationView = Whisper.View.extend({
                 'onOutgoingVideoCallInConversation: call is deemed "safe". Making call'
               );
               await window.Signal.Services.calling.startCallingLobby(
-                conversation,
+                this.model.id,
                 isVideoCall
               );
               window.log.info(
diff --git a/ts/window.d.ts b/ts/window.d.ts
index 99114c0e85cb..3e654d57c574 100644
--- a/ts/window.d.ts
+++ b/ts/window.d.ts
@@ -27,7 +27,6 @@ import * as Crypto from './Crypto';
 import * as RemoteConfig from './RemoteConfig';
 import * as zkgroup from './util/zkgroup';
 import { LocalizerType, BodyRangesType, BodyRangeType } from './types/Util';
-import { CallHistoryDetailsType } from './types/Calling';
 import { ColorType } from './types/Colors';
 import { ConversationController } from './ConversationController';
 import { ReduxActions } from './state/types';
@@ -409,11 +408,6 @@ declare global {
         ProgressModal: typeof ProgressModal;
         Quote: any;
         StagedLinkPreview: any;
-
-        getCallingNotificationText: (
-          callHistoryDetails: unknown,
-          i18n: unknown
-        ) => string;
       };
       OS: {
         isLinux: () => boolean;