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
Pappus of Alexandria Pappus of Alexandria Pappus of Alexandria (; ; ) was one of the last great Greek mathematicians of Antiquity, known for his "Synagoge" (Συναγωγή) or "Collection" (), and for Pappus's hexagon theorem in projective geometry. Nothing is known of his life, other than, (from his own writings) that he had a son named Hermodorus, and was a teacher in Alexandria. "Collection", his best-known work, is a compendium of mathematics in eight volumes, the bulk of which survives. It covers a wide range of topics, including geometry, recreational mathematics, doubling the cube, polygons and polyhedra. Pappus was active in the 4th