Constantinople (Greek: Κωνσταντινούπολις, Konstantinoúpolis; Latin: Constantinopolis; Ottoman Turkish: قسطنطینیه,Qostantiniyye; and modern Turkish: İstanbul) was the capital of the Eastern Roman Empire, the Latin and the Ottoman Empires. It was founded in AD 330, at ancient Byzantium as the new capital of the Roman Empire by Constantine I, after whom it was named. The city was the largest and wealthiest European city of the Middle Ages, and shared the glories of the Byzantine Empire, which was eventually reduced to the city and its environs.
Although besieged on numerous occasions by various peoples, it was taken only in 1204 by the army of the Fourth Crusade, in 1261 by Michael VIII, and in 1453 by the Ottoman Sultan Mehmed II. An inner wall was erected by Constantine I, and the city was surrounded by a triple wall of fortifications, begun during the 5th century by Theodosius II. The city was built on seven hills as well as on the Bosphorus, and thus presented an impregnable fortress enclosing magnificent palaces, domes and towers. The Church of Hagia Sophia, the sacred palace of the emperors, the hippodrome, and theGolden Gate were among the largest of the many churches, public edifices, and monuments lining the arcaded avenues and squares.