Hieromartyr Proterius of Alexandria (died 457), Patriarch of Alexandria (451–457), was elected by the Council of Chalcedon in 451 to replace Dioscorus of Alexandria, who had been deposed by the same council (cf. Evagrius Scholasticus, Ecclesiastical History, book 2, chapter 5 ). His accession marks the beginning of the Schism of 451 between the Coptic Orthodox and the Greek Orthodox patriarchs of Alexandria, which has never been completely resolved. Because the church of Alexandria was largely anti-Chalcedonian, the deposition of Dioscorus, a anti-Chalcedonian, from the Patriarchate, and the elevation of Proterius, a Chalcedonian, to it, was violently opposed. Finally in 457 the anti-Chalcedonian party in Alexandria elected Timothy Aelurus as Patriarch of Alexandria, in opposition to Proterius, who was subsequently martyred by Coptic mobs (Evagrius Scholasticus, 2, 8 ). He is regarded as a Saint by the Eastern Orthodox Church. He is not recognised as a Pope by the Coptic Orthodox, who instead recognize Dioscorus and Timothy as having been the legitimate Popes during this time. (Coptic Orthodox Church Network, Popes Chronology ).