Orientation
Istanbul is divided in three by the north-south Bosphorus Strait Istanbul Bogazi, the dividing line between Europe and Asia, the estuary of the Golden Horn Haliç bisecting the western part and the Sea of Marmara Marmara Denizi forming a boundary to the south. Most sights are concentrated in the old city on the peninsula of Sultanahmet, to the west of the Bosphorus between the Horn and the Sea. Across the Horn to the north are Galata, Beyoğlu and Taksim, the heart of modern Istanbul, while Kadıköy is the major district on the comparatively less-visited Anatolian side of the city. The Black Sea forms the northern boundary of Istanbul.
History
Expanding the ancient Greek colony of Byzantium by the order of the Roman Emperor Constantine the Great, the imperial city of Constantinople was for nearly a thousand years the last remaining outpost of the Roman later termed Eastern Roman or Byzantine Empire. It was finally conquered by the Ottoman Sultan Mehmed II on May 29th, 1453, an event sometimes used to mark the end of the Middle Ages. It was the nerve center for military campaigns that were to enlarge the Ottoman Empire dramatically. By the mid 1500s, Istanbul, with a population of almost half a million, was a major cultural, political, and commercial center. Ottoman rule continued until it was defeated in WWI and Istanbul was occupied by the allies. When the Republic of Turkey was born in 1923 after the War of Independence, Kemal Atatürk moved its capital to the city of Ankara. However, Istanbul has continued to expand dramatically; today its population is approximately 14 million and increases at an estimated 400,000 immigrants per year. Industry has expanded even as tourism has grown. It continues to be a city that creates its own history at the intersection where both continents meet.