Istanbul is the city that straddles Europe and Asia across the Bosporus.
The Bosporus is a narrow strait connecting the Black Sea with the Sea of Marmara. Istanbul’s historic centre lies on the European side, while substantial districts extend across the water in Asia. Bridges, ferries and tunnels connect the two parts of the metropolitan area.
The city was known as Byzantium in antiquity and later as Constantinople. It served as the capital of the Byzantine Empire and, after 1453, the Ottoman Empire. The city’s historic areas include landmarks such as Hagia Sophia, the Blue Mosque and the Topkapı Palace.
Ankara is the capital of modern Turkey, but Istanbul is the country’s largest city and most prominent international centre. Istanbul is therefore a geographic and historical crossroads, rather than Turkey’s political capital.