Christianity in Turkey
Constantinople became established in the ecclesiastical hierarchy at the Council of Constantinople in 381. Second only to Rome, the legendary origins of the Patriarchate of Constantinople go back to St. Andrew, Metrophanes and Alexander of Constantinople. Constantinople's primacy over the Patriarchates of Alexandria and Antioch was reaffirmed at the Council of Chalcedon in 481, after which the papacy in Rome supported Constantinople in its dispute with Alexandria over monophysitism. Later, when Rome sought to assert its primacy over Byzantium, the Eastern Orthodox church developed the doctrine of pentarchy as a response.
Hippodrome of Constantinople
Although the Hippodrome is usually associated with Constantinople's days of glory as an imperial capital, it actually predates that era. The first Hippodrome was built when the city was called Byzantium, and was a provincial town of moderate importance. In AD 203 the Emperor Septimius Severus rebuilt the city and expanded its walls, endowing it with a hippodrome, an arena for chariot races and other entertainment.