From its origin as a small Anatolian beylik around 1300 to its dissolution in 1922, the Ottoman Empire ruled, at various points, the entire Balkan peninsula, much of the Middle East, North Africa, and the eastern Mediterranean — a multinational, multireligious polity that lasted six centuries and survived more existential crises than any other early modern state. Its capital, Constantinople, taken from the Byzantines in 1453, was the largest city in Europe for most of its run.
The Ottomans developed a remarkable governance technology — the millet system — under which non-Muslim communities (Greek Orthodox, Armenian, Jewish, and others) administered their own religious law and internal affairs, paying a special tax in exchange for autonomy. It was not equality, but it was a working multi-confessional order at a time when Western Europe was incinerating itself over Catholic-Protestant differences. The empire's military innovations — the Janissaries, an elite slave-soldier corps recruited from Christian boys — let it dominate sixteenth-century European warfare; Suleiman the Magnificent reached the gates of Vienna in 1529. The slow Ottoman decline, conventionally dated from the second failed siege of Vienna in 1683, was not a single collapse but a century-long compression — losing the Balkans piece by piece, the Arab provinces in the First World War, and finally being dismembered by the Allied powers in 1920. The Republic of Turkey emerged from the wreckage in 1923.
Almost every modern Middle Eastern conflict — the Israeli-Palestinian dispute, the Syrian civil war, the Lebanese confessional system, the Kurdish question — sits on top of Ottoman boundaries that the British and French redrew badly after 1918. The recovery of Ottoman administrative records is now one of the most active areas in the historiography of the modern Middle East.