With approximately 15 million people, Istanbul is Turkey's most populous city. The modern city covers both European and Asian sides of the Bosporus.
Founded by Roman emperor Constantine on the site of the ancient Greek colony of Byzantium, it became the eastern capital of the Roman Empire and later the capital of the Byzantine Empire. After the Fall of Constantinople in 1453 it became part, and soon capital, of the Ottoman Empire. The city was known as Byzantium in ancient times and Constantinople by westerners until 1930.
Tourist attractions include Sariyer, Eyüp and Taksim on the European side, and Beykoz, Üsküdar, Kadiköy, Moda, Bostanci and the Prince's Islands on the Asian side.
Istanbul is no longer the capital of Turkey, but it is convincingly the most significant city in terms of Turkish culture, industry and commerce, and the most important export and import center.