Istanbul

What it's known for

Istanbul is Türkiye's largest city and its economic, cultural and historical centre. Under the name Constantinople it was the capital of the Byzantine Empire and then of the Ottoman Empire.

Fun facts

1. Greek settlers from Megara founded the city as Byzantium in the 7th century BC.
2. The Hagia Sophia was opened as a cathedral in 537 under Emperor Justinian I and was turned into a mosque after the Ottoman conquest in 1453.
3. The name Constantinople was used for about 1,600 years, until İstanbul became the official name on 28 March 1930.