Ottoman Empire

The Ottoman Empire was founded by Osman I in northwestern Anatolia around 1299 and grew into one of the most durable multi-ethnic, multi-religious empires in world history. Its conquest of Constantinople in 1453 under Mehmed II ended the Byzantine Empire and gave the Ottomans control of a key juncture between Europe and Asia. At its territorial peak in the 16th and 17th centuries, under sultans such as Süleyman the Magnificent (r. 1520–1566), the empire stretched from Hungary and the Balkans through Anatolia, the Levant, Egypt, the Hejaz, Mesopotamia, and much of North Africa.

The state was headed by a sultan who, after 1517, also claimed the title of caliph following the conquest of the Mamluk Sultanate. Administration combined a centralized bureaucracy with the millet system, which granted recognized religious communities (Orthodox Christians, Armenians, Jews, and others) substantial autonomy over personal-status law. The devşirme levy recruited Christian boys from the Balkans into the Janissary corps and the imperial administration.

From the late 18th century onward the empire faced sustained military defeats, nationalist independence movements (Greek, Serbian, Bulgarian, Arab), and growing economic dependence on European powers — earning it the label "the sick man of Europe." The Tanzimat reforms (1839–1876) attempted modernization, and the 1908 Young Turk Revolution restored constitutional rule. During World War I the Ottomans allied with the Central Powers; the war years also saw the Armenian Genocide of 1915–1916, recognized as such by many states and scholars.

Defeat led to the Armistice of Mudros (1918), the punitive Treaty of Sèvres (1920), and Allied occupation. The Turkish War of Independence under Mustafa Kemal (Atatürk) overturned that settlement, replaced by the Treaty of Lausanne (1923). The sultanate was abolished on 1 November 1922 and the caliphate on 3 March 1924, with the Republic of Turkey proclaimed on 29 October 1923. Ottoman borders and minority arrangements continue to shape disputes across the Balkans, Cyprus, the Levant, and the Caucasus.