--- a/browser/components/downloads/DownloadsCommon.jsm
+++ b/browser/components/downloads/DownloadsCommon.jsm
@@ -73,16 +73,18 @@ const kDownloadsStringsRequiringFormatti
 };
 
 const kDownloadsStringsRequiringPluralForm = {
   otherDownloads3: true
 };
 
 const kPartialDownloadSuffix = ".part";
 
+const kMaxHistoryResultsForLimitedView = 42;
+
 const kPrefBranch = Services.prefs.getBranch("browser.download.");
 
 var PrefObserver = {
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
                                          Ci.nsISupportsWeakReference]),
   getPref(name) {
     try {
       switch (typeof this.prefs[name]) {
@@ -188,23 +190,32 @@ this.DownloadsCommon = {
    * Get access to one of the DownloadsData, PrivateDownloadsData, or
    * HistoryDownloadsData objects, depending on the privacy status of the
    * specified window and on whether history downloads should be included.
    *
    * @param window
    *        The browser window which owns the download button.
    * @param [optional] history
    *        True to include history downloads when the window is public.
+   * @param [optional] privateAll
+   *        Whether to force the public downloads data to be returned together
+   *        with the private downloads data for a private window.
+   * @param [optional] limited
+   *        True to limit the amount of downloads returned to
+   *        `kMaxHistoryResultsForLimitedView`.
    */
-  getData(window, history = false) {
-    if (PrivateBrowsingUtils.isContentWindowPrivate(window)) {
+  getData(window, history = false, privateAll = false, limited = false) {
+    let isPrivate = PrivateBrowsingUtils.isContentWindowPrivate(window);
+    if (isPrivate && !privateAll) {
       return PrivateDownloadsData;
     }
     if (history) {
-      return HistoryDownloadsData;
+      if (isPrivate && privateAll)
+        return LimitedPrivateHistoryDownloadData;
+      return limited ? LimitedHistoryDownloadsData : HistoryDownloadsData;
     }
     return DownloadsData;
   },
 
   /**
    * Initializes the Downloads back-end and starts receiving events for both the
    * private and non-private downloads data objects.
    */
@@ -631,31 +642,40 @@ XPCOMUtils.defineLazyGetter(DownloadsCom
  *
  * Note that using this object does not automatically initialize the list of
  * downloads. This is useful to display a neutral progress indicator in
  * the main browser window until the autostart timeout elapses.
  *
  * This powers the DownloadsData, PrivateDownloadsData, and HistoryDownloadsData
  * singleton objects.
  */
-function DownloadsDataCtor({ isPrivate, isHistory } = {}) {
+function DownloadsDataCtor({ isPrivate, isHistory, maxHistoryResults } = {}) {
   this._isPrivate = !!isPrivate;
 
   // Contains all the available Download objects and their integer state.
   this.oldDownloadStates = new Map();
 
   // For the history downloads list we don't need to register this as a view,
   // but we have to ensure that the DownloadsData object is initialized before
   // we register more views. This ensures that the view methods of DownloadsData
   // are invoked before those of views registered on HistoryDownloadsData,
   // allowing the endTime property to be set correctly.
   if (isHistory) {
+    if (isPrivate) {
+      PrivateDownloadsData.initializeDataLink();
+    }
     DownloadsData.initializeDataLink();
-    this._promiseList = DownloadsData._promiseList
-                                     .then(() => DownloadHistory.getList());
+    this._promiseList = DownloadsData._promiseList.then(() => {
+      // For history downloads in Private Browsing mode, we'll fetch the combined
+      // list of public and private downloads.
+      return DownloadHistory.getList({
+        type: isPrivate ? Downloads.ALL : Downloads.PUBLIC,
+        maxHistoryResults
+      });
+    });
     return;
   }
 
   // This defines "initializeDataLink" and "_promiseList" synchronously, then
   // continues execution only when "initializeDataLink" is called, allowing the
   // underlying data to be loaded only when actually needed.
   this._promiseList = (async () => {
     await new Promise(resolve => this.initializeDataLink = resolve);
@@ -830,16 +850,25 @@ DownloadsDataCtor.prototype = {
     browserWin.DownloadsPanel.showPanel();
   }
 };
 
 XPCOMUtils.defineLazyGetter(this, "HistoryDownloadsData", function() {
   return new DownloadsDataCtor({ isHistory: true });
 });
 
+XPCOMUtils.defineLazyGetter(this, "LimitedHistoryDownloadsData", function() {
+  return new DownloadsDataCtor({ isHistory: true, maxHistoryResults: kMaxHistoryResultsForLimitedView });
+});
+
+XPCOMUtils.defineLazyGetter(this, "LimitedPrivateHistoryDownloadData", function() {
+  return new DownloadsDataCtor({ isPrivate: true, isHistory: true,
+    maxHistoryResults: kMaxHistoryResultsForLimitedView });
+});
+
 XPCOMUtils.defineLazyGetter(this, "PrivateDownloadsData", function() {
   return new DownloadsDataCtor({ isPrivate: true });
 });
 
 XPCOMUtils.defineLazyGetter(this, "DownloadsData", function() {
   return new DownloadsDataCtor();
 });