Istanbul, historically known as Constantinople and Byzantium, is a city in Turkey. It is the largest city in the country and is also the 5th largest city proper in the world. Istanbul has an estimated population of over 12.6 Million. It serves as the financial and cultural center of Turkey and is also considered a Mega City.

Founded in 667 BC as Byzantium, Istanbul is one of the oldest and most historically significant cities in the world. It has also served as an important capital of the Roman Empire. Currently, it belongs to the province of the same name and to the region of Maramara, Turkey. In 1985, its historic sites became registered UNESCO World Heritage sites.

The current economy of Istanbul is diverse with industries ranging from service and manufacturing to trade and transportation. At present, Istanbul generates up to 55% of the trade in Turkey. The city´s history has also helped it become a significant tourist destination.