From its origin as a small Anatolian beylik around 1300 — one of dozens of frontier warlordships left after the Mongols shattered the Seljuks — 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 by Mehmed II in 1453 in a siege that ended the thousand-year Roman East, was the largest city in Europe for most of its run and a hinge between three continents.
The Ottomans developed a remarkable governance technology — the millet system — under which non-Muslim communities (Greek Orthodox, Armenian Apostolic, Jewish, and others) administered their own religious law and internal affairs through their own clergy, paying a special poll tax, the jizya, 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 in the Wars of Religion. The empire's military innovations — the Janissaries, an elite slave-soldier corps recruited as boys from Christian villages through the devshirme levy, converted and trained to answer only to the sultan — let it dominate sixteenth-century European warfare; Suleiman the Magnificent reached the gates of Vienna in 1529, codified its law, and made the empire the terror and admiration of Christendom. Power was sustained by a salaried provincial cavalry holding timar land grants in return for service, and checked by recurring crises of succession that often ended in fratricide. 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 to nationalist revolts and Russian armies, surviving the failed nineteenth-century Tanzimat reforms meant to centralize and modernize it, the loss of the Arab provinces in the First World War, and finally being dismembered by the Allied powers in the 1920 Treaty of Sèvres. The Republic of Turkey, forged by Atatürk after the War of Independence overturned that treaty, 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 in the 1916 Sykes-Picot agreement and after. Erdoğan's invocations of Ottoman grandeur, and Greece's and Armenia's long memories of Ottoman rule, keep the empire politically alive; the recovery of its vast administrative archives in Istanbul is now one of the most active areas in the historiography of the modern Middle East.