The Ottoman story begins modestly, in the rolling terrain of northwestern Anatolia around 1299. Osman I, a Turkoman tribal leader on the frontier of the crumbling Byzantine Empire, led a small principality called a beylik. His followers — Turkish tribal groups and Byzantine renegades, Muslims and converts alike — expanded by raiding and conquering. His son Orhan captured Bursa in 1326. The Ottomans crossed into Europe by the mid-14th century. The Battle of Kosovo in 1389 ended Serbian power in the Balkans. By the time Mehmed II conquered Constantinople in 1453, the Ottomans had been at this for a century and a half. What followed was acceleration: under Selim I and his son Suleiman the Magnificent (1520–1566), the empire became a genuine superpower. Suleiman captured Belgrade, defeated the Hungarians at Mohács in 1526, besieged Vienna in 1529, and took Baghdad from the Persians in 1535. His navy dominated the Mediterranean. At Suleiman's death, the empire spanned approximately three continents.

Ottoman expansion was not merely military — it was also demographic, and its methods were often brutal by any era's standards. Early conquests in the Balkans were characterized by what some 21st-century historians describe as an *akıncı* phase of continuous raiding, slave-taking, and destruction, followed by administrative integration. The Devshirme system recruited Christian boys — one from every forty families in the Balkans — between the ages of eight and twenty, separating them from their families, converting them to Islam, and training them for the Ottoman military and civil service. On Cyprus in 1570, after the city of Nicosia fell, some 20,000 inhabitants were massacred and tens of thousands more were enslaved across the island. The Barbary corsairs of North Africa, nominally under Ottoman suzerainty, captured thousands of merchant ships and enslaved the crews. These are not footnotes to Ottoman history; they are part of its structure. At the same time, the empire offered something relatively rare in medieval and early modern Europe: a degree of religious tolerance. Mehmed II allowed the Eastern Orthodox Church to maintain its autonomy. Jewish communities expelled from Spain in 1492 found refuge in Istanbul and Salonica. The empire's millet system permitted different religious communities to govern their own affairs under Islamic law.

The cliché of Ottoman decline — that the empire peaked under Suleiman and crumbled steadily afterward — has been largely rejected by modern historians, who see a more flexible and adaptive state through much of the 17th and 18th centuries. But decline did come, and when it came, it was stark. Military defeats mounted from the late 18th century onward. Greece won independence in 1829. Serbia, Romania, Bulgaria, and Montenegro followed over the next decades. The Ottoman state, forced to modernize its army and infrastructure, borrowed heavily from European banks and declared bankruptcy in 1875. By 1881, European creditors through the Ottoman Public Debt Administration controlled significant portions of the imperial economy. From 1894 to 1896, between 100,000 and 300,000 Armenians throughout the empire were killed in what became known as the Hamidian massacres. Then came World War I, in which the empire joined the German-led Central Powers — and the worst chapter of all: the Armenian genocide of 1915, in which the Ottoman government and Kurdish irregulars killed up to 1.5 million Armenians through massacre, forced labor, and death marches into the Syrian desert. Large-scale massacres were also carried out against Greek and Assyrian minorities in the same campaign of ethnic cleansing.

The empire that Osman I founded in the hills of northwestern Anatolia was formally abolished on 1 November 1922. The last sultan, Mehmed VI, left Istanbul by ship seventeen days later. The Republic of Turkey was proclaimed on 29 October 1923, with Ankara as its capital and Mustafa Kemal Atatürk as its first president. The caliphate — the religious leadership of the Muslim world that the Ottoman sultans had claimed — was abolished in March 1924. Six centuries, thirty-six sultans, three continents. What remains in Istanbul is architectural: the mosques and palaces and hans and hammams that the empire built across the city it loved most. Hagia Sophia, whose fate Mehmed II determined on the afternoon he rode through its doors in 1453, has been a church, a mosque, a museum, and a mosque again. The building has outlasted everything. Perhaps that is fitting for a city where history does not end so much as it accumulates.