Constantinople (; ; ; modern ; ) was the
capital city of the
Roman/
Byzantine (330–1204 and 1261–1453), the
Latin (1204–1261), and the
Ottoman (1453–1924)
empires. It was reinaugurated in 324 AD at ancient
Byzantium, as the new capital of the
Roman Empire by Emperor
Constantine the Great, after whom it was named, and dedicated on 11 May 330. In the 12th century, the city was the largest and wealthiest European city and it was instrumental in the advancement of
Christianity during Roman and Byzantine times. After the loss of its territory, the
Eastern Roman (Byzantine) Empire was reduced to just its capital city and its environs, eventually
falling to the
Ottomans in 1453. Following the
Muslim conquest, the former bastion of Christianity in the east, Constantinople, was turned into the capital of the
Ottoman Empire, under which it prospered and flourished again. For many centuries the city was popularly called "Istanbul", from a Greek phrase meaning "to the city" , while officially it was known under various names, including Constantinople and Dersaadet. Names other than "Istanbul" became obsolete in late Ottoman Empire, and after Turkey switched to Latin script in 1928, it began to urge other countries to use the Turkish name, and "Istanbul" gradually attained international usage.