Michaelion

The Michaelion was one of the earliest and most famous sanctuaries dedicated to Saint Michael the Archangel in the Roman Empire.

[3][4] According to a widespread tradition, current already since the 6th century, the Church of St. Michael at Sosthenion was founded by Constantine the Great, who visited the temple, erected by the Argonauts and dedicated to Zeus Sosthenios or a winged deity.

After sleeping the night in the temple, Constantine reported a vision that the angel was the Archangel Michael, and converted the building into a church to honor him.

[5][6][7][8] However, according to the French scholar Raymond Janin, this tradition is most probably later invention, created in competition with the other great shrine to Michael, at nearby Anaplous, which was of earlier date.

[6] It is certain however that the church of St. Michael existed at the turn of the 6th century, for the rebel Vitalian made it his headquarters and Emperor Anastasius I (r. 491–518) visited it in 515.

[10] During the reign of the next several emperors after Constantine, the number of churches dedicated to Archangel Michael in Constantinople increased to fifteen.