The <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Papal_conclave,_1846" id="mwkw" rel="mw:WikiLink" title="Papal conclave, 1846">Papal conclave of 1846</a> elects <a href="https://en.wikipedia.org/wiki/Pope_Pius_IX" id="mwlA" rel="mw:WikiLink" title="Pope Pius IX">Pope Pius IX</a>, beginning the longest reign in the history of the papacy.