The Palace of Antiochos () was an early 5th-century palace in the Byzantine capital, Constantinople (modern Istanbul, Turkey). It has been identified with a palatial structure excavated in the 1940s and 1950s close to the Hippodrome of Constantinople, some of whose remains are still visible today. In the 7th century, a part of the palace was converted into the church–more properly a martyrion, a martyr's shrine–of St Euphemia in the Hippodrome (, Hagia Euphēmia en tō Hippodromiō), which survived until the Palaiologan period. History Antiochos's palace The palace of Antiochos was constructed as a residence for Antiochos, a eunuch of Persian origin, who enjoyed considerable influence during the reign of Theodosius II (r. 402–450). As a cubicularius (chamberlain), he was tutor to the young emperor and eventually rose to the post of praepositus sacri cubiculi and the rank of patricius. His overbearing attitude and dominance over the young emperor caused his downfall (the date is disputed) by the emperor's sister, Pulcheria, but he was allowed to return to his palace and live there. He remained active in the capital's politics until he finally fell from grace and entered the clergy in ca. 439. Following this, his property, including the palace, was confiscated by the emperor. The palace was first discovered in 1939, when frescoes depicting the life of Saint Euphemia were discovered northwest of the Hippodrome. Further excavations in 1942 by Alfons Maria Schneider uncovered a hexagonal hall opening to a semicircular portico, while excavations in 1951–52 under R. Duyuran uncovered a column base with the inscription "of the praepositus Antiochos", which allowed for the identification of the site. Based on the stamps on the bricks recovered from the site, J. Bardill proposes a date of construction not earlier than 430. Church of Saint Euphemia The Church of Saint Euphemia in the Hippodrome (also known as lying "in ta Antiochou", i.e. "the quarters/palaces of Antiochos") 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. Originally the western chapel had frescoes depicting the martyrdom of Saint Euphemia, and the sanctuary had a canopy dome. During the Byzantine Iconoclasm, the building was secularized and allegedly converted into a store of arms and manure. According to tradition, the bones of the saint were ordered thrown into the sea