Constantinople
Constantinople (Greek: Κωνσταντινούπολις, Κωνσταντινούπολη - Konstantinoúpolis, Konstantinoúpoli; Latin: Constantinopolis; Ottoman Turkish: قسطنطینیه, Kostantiniyye; and modern Turkish: İstanbul) was the capital city of the Eastern Roman or Byzantine Empire, the Latin and the Ottoman Empire. It was founded in AD 330, at ancient Byzantium as the new capital of the Roman Empire by Constantine the Great, after whom it was named. In the 1100s, the city was the largest and wealthiest European city of the Middle Ages, its only other European rival in the period being Cordova, Spain (900-1100 AD). Eventually, the empire of Christian Eastern Orthdoxy in the east was reduced to just the capital and its environs, falling to the Muslims in the historic battle of 1453.
Read more about Constantinople.