Secret Treaty of Vienna
... that in the 1815 Secret Treaty of Vienna, Britain and Austria sided with their former enemy France against former allies Prussia and Russia?
... that in the 1815 <b id="mwB7o"><a href="./Secret_Treaty_of_Vienna" id="mwB7s" rel="mw:WikiLink" title="Secret Treaty of Vienna">Secret Treaty of Vienna</a></b>, Britain and Austria sided with their former enemy France against former allies Prussia and Russia?