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 popular speech, the most common way of referring to it came to be simply "the City" (Greek: "hē Polis", , Modern Greek: "i Poli", η Πόλη). This usage, still current today in colloquial Greek and Armenian (Պոլիս, pronounced "Polis" or "Bolis" in the Western Armenian dialect prevalent in the city), also became the source of the later Turkish name, "Istanbul" (see below). "Kostantiniyye" (Arabic, Persian , "Qusṭanṭīniyya", Ottoman Turkish , "Ḳosṭanṭīnīye") is the name by which the city came to be known in the Islamic world. It is an Arabic calqued form of "Constantinople", with an Arabic ending meaning 'place