The Church of St Euphemia in the Hippodrome (also known as lying in ta Antiochou, i.e. "the quarters/palaces of Antiochos"[4]) was established in the hexagonal hall probably sometime in the early 7th century, when the original church at Chalcedon was destroyed during the Sassanid Persian invasions, and the relics moved for safety to Constantinople.[7][8] During the Byzantine Iconoclasm, the building was secularized and allegedly converted into a store of arms and manure.[9] According to tradition, the bones of the saint were ordered thrown into the sea by Emperor Leo III the Isaurian (r. 717–741) or by his son, Constantine V (r. 741–775). They were however saved by two pious brothers, and brought to the island of Lemnos, from where they were brought back in 796 by Empress Eirene (r. 797–802).