Alexander himself faced three primary challenges during his patriarch term. The first of these was a schismatic sect, led by Erescentius, which disputed the timing of Easter. Alexander found himself put in the position of writing a special treatise on the controversy, in which he cited earlier statements regarding the matter by Dionysius of Alexandria. Alexander's own efforts, while they did serve to quiet the dispute, were not enough to quiet the controversy themselves, although the First Council of Nicaea, held during his tenure, did resolve the matter.