The biggest city in modern Turkey has been a cross-roads of European, Asian and world history for many centuries. Powerful empires have one after another, in an unbroken chain dating back as far 667 BC, made it one of the centres of their world and a hotbed of political, religious and artistic activity. Its strategically advantageous position on the Bosphorus peninsula between the Balkans and Anatolia, the Black Sea and the Mediterranean is its major strength.
The city's masterpieces are too many to list, but the main ones are probably the Hippodrome of Constantine, the 6th-century Hagia Sophia and the 16th-century Süleymaniye Mosque. An ever-burgeoning population as well as pollution and uncontrolled urbanization all pose modern threats to the survival of its historic buildings and sites.