The Ottoman Empire

Osman I Founds the Ottoman State

Around 1299, a Turkish frontier chieftain named Osman I carved out a small principality (beylik) in northwest Anatolia, on the fraying edge of the Byzantine Empire. His followers took his name — Osmanli, or Ottomans.

Why it matters: From this tiny warband on a contested border would grow one of the largest and longest-lived empires in history, lasting more than 600 years.

Orhan, Bursa, and the Crossing into Europe

Osman's son Orhan captured Bursa in 1326 and made it the Ottoman capital, then seized Byzantine cities across Anatolia. By 1354 the Ottomans had crossed the Dardanelles at Gallipoli, gaining their first foothold in Europe.

Why it matters: The leap into Europe transformed a regional beylik into a power poised to swallow the Balkans and, one day, Constantinople itself.

The Janissaries and the Devshirme

The Ottomans built an elite standing army, the Janissaries, through the devshirme — a levy of Christian boys from the Balkans who were converted to Islam and trained as fiercely loyal soldiers of the sultan.

Why it matters: The Janissaries were among the first modern standing armies in Europe and the disciplined core of Ottoman power for centuries.

The Battle of Kosovo

At the Battle of Kosovo in 1389, Sultan Murad I broke a Serbian-led coalition and secured Ottoman dominance over the Balkans — though Murad himself was killed at the moment of victory.

Why it matters: Kosovo cemented Ottoman rule in southeastern Europe and became a defining, near-mythic memory in Serbian national identity.

The Battle of Nicopolis

In 1396 Sultan Bayezid I 'the Thunderbolt' annihilated a grand crusader army of French, Hungarian and other European knights at Nicopolis, in what is now Bulgaria.

Why it matters: Nicopolis was the last great crusade — and its catastrophic failure showed that Christian Europe could not halt the Ottoman advance by force of arms.

Timur and the Ottoman Interregnum

In 1402 the Central Asian conqueror Timur (Tamerlane) crushed the Ottomans at the Battle of Ankara and captured Sultan Bayezid I. The empire fractured into a decade of civil war known as the Interregnum before Mehmed I reunited it.

Why it matters: The Ottomans came within a hair of destruction — yet recovered so completely that within fifty years they would take Constantinople.

Mehmed II Conquers Constantinople

In 1453, 21-year-old Sultan Mehmed II besieged Constantinople with giant bronze cannons and took the thousand-year-old capital of the Byzantine Empire. He made the city — Istanbul — his new capital.

Why it matters: The fall of Constantinople ended the Byzantine Empire and the Middle Ages for many historians, and announced the Ottomans as a world power.

Selim I, the Mamluks, and the Caliphate

Sultan Selim I doubled the empire's size, crushing the Mamluk Sultanate to seize Egypt, Syria and the Hejaz in 1516–17. With the holy cities of Mecca and Medina now under Ottoman rule, the sultans claimed the title of caliph — leader of the Muslim world.

Why it matters: Selim's conquests made the Ottomans the dominant power in the Islamic world, a claim to the caliphate they held until the empire's end.

Suleiman the Magnificent

Under Suleiman the Magnificent, the empire reached its zenith, stretching from Hungary to the Persian Gulf and from Crimea to North Africa. His armies took Belgrade and Rhodes and dominated the Mediterranean.

Why it matters: Suleiman's 46-year reign was the high noon of Ottoman power — militarily, politically and culturally the empire's golden age.

The Siege of Vienna

In 1529 Suleiman marched on Vienna, the gateway to central Europe. Overextended supply lines, heavy rains and a determined defense forced the Ottomans to withdraw from the city's walls.

Why it matters: Vienna marked the high-water mark of Ottoman expansion into the heart of Europe — the point where the tide of conquest was first checked.

Suleiman the Lawgiver and the Golden Age

To Europeans he was 'the Magnificent,' but to his own people Suleiman was Kanuni — 'the Lawgiver.' He systematized Ottoman law, and his reign saw a flowering of poetry, calligraphy and monumental architecture in Istanbul.

Why it matters: The Ottoman golden age rivaled the European Renaissance, blending Islamic, Byzantine and Persian traditions into a brilliant imperial culture.

The Battle of Lepanto

In 1571 a Christian 'Holy League' fleet destroyed the Ottoman navy at the Battle of Lepanto — the last great clash of oar-powered galleys. The Ottomans rebuilt their fleet within a year, but the spell of invincibility was broken.

Why it matters: Lepanto was Europe's first major victory over the Ottomans, a huge psychological boost for Christendom even as Ottoman power endured.

The Second Siege of Vienna and the Great Retreat

In 1683 the Ottomans besieged Vienna a second time, only to be routed when a Polish-led relief army charged down from the hills. It was the beginning of a long retreat from central Europe.

Why it matters: The failure at Vienna turned the tide permanently: for the first time the Ottomans began losing large territories rather than gaining them.

The Treaty of Karlowitz

The Treaty of Karlowitz in 1699 forced the Ottomans to surrender Hungary and other lands to their European enemies — the first time the empire signed away large territories in defeat.

Why it matters: Karlowitz marked the turning point from an expanding empire to a shrinking one, beginning two centuries of slow decline.

The Empire in Retreat

Through the 18th and 19th centuries the Ottomans lost ground to Russia and Austria and to rising nationalism: Greece won independence, Egypt gained autonomy, and Balkan peoples broke away one by one.

Why it matters: As the empire fragmented, the European powers began quarreling over how to divide its lands — the so-called 'Eastern Question.'

The Tanzimat Reforms and the 'Sick Man of Europe'

To survive, the Ottomans launched the Tanzimat ('reorganization') reforms from 1839, modernizing the army, law, education and administration and granting new rights to non-Muslim subjects. Even so, a Russian tsar dubbed the empire 'the sick man of Europe.'

Why it matters: The reforms modernized the state but could not stop the decline — or satisfy the nationalist movements pulling the empire apart.

The Young Turk Revolution

In 1908 the Young Turks — reform-minded officers and intellectuals — forced the autocratic Sultan Abdul Hamid II to restore the constitution and parliament, seizing effective control of the crumbling state.

Why it matters: The revolution was a last attempt to save the empire through nationalism and modernization, but it soon led it into a catastrophic world war.

World War I and the Armenian Genocide

The Ottomans entered World War I on Germany's side in 1914. Amid the war, the government carried out the systematic deportation and mass murder of its Armenian population — the Armenian Genocide — in which an estimated 1.5 million Armenians died.

Why it matters: The genocide is widely regarded as the first modern genocide. The disastrous war, meanwhile, shattered what remained of Ottoman power.

How we know: Documented extensively by survivors, diplomats and historians; recognized as genocide by most scholars, though the Turkish state disputes the term.

The Fall of the Empire and the Republic of Turkey

Defeated and occupied after WWI, the empire was saved from partition by a nationalist movement under Mustafa Kemal (Atatürk). The sultanate was abolished in 1922, and in 1923 the Republic of Turkey was proclaimed — a secular nation-state on the empire's Anatolian heartland.

Why it matters: After more than six centuries, the Ottoman Empire ended — and from its ashes rose modern Turkey and much of the map of today's Middle East.