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
Strait of Tartary (1832–54). On Russian maps, the short narrowest section of the strait (south of the mouth of the Amur) is called Nevelskoy Strait, after Admiral Gennady Nevelskoy, who explored the area in 1848; the body of water north of there, into which the Amur River flows, is the Amur Liman; and the name of "Strait of Tartary" is reserved for the largest section of the body of water, south of Nevelskoy Strait. The Tartar Strait was a puzzle to European explorers since, when approached from the south, it becomes increasingly shallow and looks like the head of a bay. In 1787