Constantinople
Constantinople (; ) was the capital city of the Roman/Byzantine Empire (330–1204 and 1261–1453), and also of the brief Crusader state known as the Latin Empire (1204–1261), until finally falling to the Ottoman Empire (1453–1923). It was reinaugurated in 324 from 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. The city was located in what is now the European side and the core of modern Istanbul.
Europe
In the east a resurgent Byzantine Empire recaptured Crete and Cyprus from the Muslims and reconquered the Balkans. Constantinople was the largest and wealthiest city in Europe from the 9th to the 12th centuries, with a population of approximately 400,000. The Empire was weakened following the defeat at Manzikert and was weakened considerably by the sack of Constantinople in 1204, during the Fourth Crusade. Although it would recover Constantinople in 1261, Byzantium fell in 1453 when Constantinople was taken by the Ottoman Empire.