The <a href="https://en.wikipedia.org/wiki/Treaty_of_Vienna_(1864)" id="mwTg" rel="mw:WikiLink" title="Treaty of Vienna (1864)">Treaty of Vienna</a> is signed, by which Denmark relinquishes one province each to <a href="https://en.wikipedia.org/wiki/Prussia" id="mwTw" rel="mw:WikiLink" title="Prussia">Prussia</a> and <a href="https://en.wikipedia.org/wiki/Austria" id="mwUA" rel="mw:WikiLink" title="Austria">Austria</a>.