Istanbul Istanbul Istanbul (, or or ; ), historically known as Byzantium and before 1924 as Constantinople, is the most populous city in Turkey and the country's economic, cultural, and historic center. Istanbul is a transcontinental city in Eurasia, straddling the Bosporus strait (which separates Europe and Asia) between the Sea of Marmara and the Black Sea. Its commercial and historical center lies on the European side and about a third of its population lives on the Asian side. The city is the administrative center of the Istanbul Metropolitan Municipality (coterminous with Istanbul Province), both hosting a population of around 15
Names of Istanbul "Constantinople" instead of "Istanbul" were no longer delivered by Turkey's PTT, which contributed to the eventual worldwide adoption of the new name. In English the name is usually written "Istanbul". In modern Turkish the name is written "İstanbul" (dotted i/İ and dotless ı/I being two distinct letters in the Turkish alphabet). "Stamboul" or "Stambul" is a variant form of "İstanbul." Greek for 'the town'. Like "Istanbul" itself, forms without the initial "i-" are attested from early on in the Middle Ages, first in Arabic sources of the 10th century and Armenian ones of the 12th. Some early sources also attest