History of Alexandria Severus after temporary abolition by Augustus. Monumental buildings were erected in Alexandria through the third century BC. The Heptastadion connected Pharos with the city and the Lighthouse of Alexandria followed soon after, as did the Serapeum, all under Ptolemy I. The Museion was built under Ptolemy II; the Serapeum expanded by Ptolemy III Euergetes; and mausolea for Alexander and the Ptolemies built under Ptolemy IV. The Ptolemies fostered the development of the Library of Alexandria and associated Musaeum into a renowned center for Hellenistic learning. Luminaries associated with the Musaeum included the geometry and number-theorist Euclid; the astronomer Hipparchus; and
Pope Dioscorus I of Alexandria Coptic Orthodox and Greek Orthodox Patriarchates of Alexandria agreed to mutually recognize baptisms performed in each other's churches. Pope Dioscorus I of Alexandria Pope Dioscorus I of Alexandria, 25th Pope of Alexandria & Patriarch of the See of St. Mark. He was deposed by the Council of Chalcedon in 451 but was recognized as Patriarch by the Coptic Church until his death. He died on the Island of Gangra, Paphlagonia, in September 454. He is venerated as a saint by the Coptic and other Oriental Orthodox churches. Dioscorus served as the dean of the Catechetical School of Alexandria, and was