Istanbul, originally known as Constantinople, is the most populous city in Turkey and the country's economic, cultural, and historical epicenter. It has a population of about 15 million people, or around 19% of Turkey's total, and it is located on both the European and Asian sides of the Bosporus. In terms of population, Istanbul has more people than any other European city and ranks 15th in the world.

In the seventh century BCE, Greek settlers from Megara established the city, naming it Byzantium (Greek: v, Byzantion). As it expanded, the city became a major hub along the Silk Road and a historical powerhouse.After the Turkish War of Independence, Ankara took over as the capital of the newly founded Republic of Turkey in 1923. In 1930, the city's name was officially changed to Istanbul, the Turkish translation of (romanized: eis tn Pólin; "to the city," the informal term used by

Greek speakers since the 11th century).

In 2022, eight years after being named a European Capital of Culture, Istanbul received over 14.75 million foreign tourists, making it the world's ninth most visited city.

Istanbul is home to several UNESCO World Heritage Sites and the headquarters of several Turkish corporations, which account for more than 30% of the Turkish economy.