Istanbul Istanbul formerly known as Constantinople, is the largest city in Turkey Constantinople Constantinople (/ˌkɒnstæntɪˈnoʊpəl/;[5] Greek: Κωνσταντινούπολις Kōnstantinoupolis; Latin: Constantinopolis; Ottoman Turkish: قسطنطينيه, romanized: Ḳosṭanṭīnīye) was the capital of the Roman/Byzantine Empire (330–1204 and 1261–1453), the Latin Empire (1204–1261), and the Ottoman Empire (1453–19...