Serapeum of Alexandria

The Serapeum of Alexandria was the chief temple of Serapis, a Graeco-Egyptian god formed from Osiris-Apis. Ptolemy I Soter promoted the cult to bind his subjects; the sanctuary was built mainly under Ptolemy III Euergetes between 246 and 222 BC.

The temple housed a daughter collection of the Library of Alexandria, and subterranean galleries served the mysteries of Serapis. Damaged in the Kitos War of AD 116, it was restored under Hadrian and rebuilt by the Romans around 181 to 217; the column misnamed Pompey's Pillar was erected for Diocletian between 298 and 302.

The Serapeum became the last great stronghold of pagan Alexandria. In 391, after Theodosius I banned temple visits, Christians led by Bishop Theophilus stormed it; the sanctuary was sacked and closed in 392, and a church and the Monastery of Metanoia later rose among its ruins.