Istanbul is the largest city in Turkey, straddling the Bosporus Strait, the boundary between Europe and Asia. It is considered the country's economic, cultural and historic capital. The city has a population of over 15 million residents, comprising 19% of the population of Turkey, and is the most populous city in Europe and the world's sixteenth-largest city. The city was founded as Byzantium in the 7th century BCE by Greek settlers from Megara.
https://en.wikipedia.org/wiki/Istanbul