🏛️ Ottoman Empire: chronology from 1299 to the Turkish republic

The history of the Ottoman Empire begins with a small principality in Anatolia. It emerged around 1299, founded by Osman I, the leader of one of the Turkic tribes (as of 09/2026, article about the dynasty's founder). Over two and a half centuries, this beylik grew into an empire on three continents, and after World War I it disappeared from the map.

Below is the full timeline: from the Seljuk legacy and the Battle of Kosovo to the republic proclaimed in the autumn of 1923 (as of 09/2026, how the republic came to be). If you are planning a trip to Turkey, this sequence of dates will explain why Istanbul looks the way it does. You will see which years were turning points and when the empire began to lose its strength.

The ottoman principality in asia minor

💡 In short:

The principality of Osman I appeared around 1299 (as of 09/2026, reference on Osman I).
It grew out of the fragments of the Seljuk Sultanate after the Mongol blow.
The state was organized along military-feudal lines.

Asia Minor was fully or partially part of various states of antiquity and the early Middle Ages. In the early 14th century, a feudal principality appeared in the northwest of the peninsula. It was named Ottoman in honor of Osman I, and the various Turkic tribes within it gradually became one people.

The Seljuk Sultanate had by then collapsed under the blows of the Mongols (as of 09/2026, history of the Ottoman state). Osman's beylik rose from its ruins. The new state was organized along military-feudal lines: the ruling class consisted of feudal lords, warriors, and sipahis. The first task was expanding its holdings and seizing new lands.

The empire was built by war, not trade. The Ottomans moved their first capital to Bursa after 1326 (as of 09/2026, reference on the early period). From there, the road to Constantinople and the Balkans lay open.

First conquests and the Battle of Kosovo

In the second half of the 14th century, Eastern Thrace and several Bulgarian cities became part of the empire. In 1389, the Ottomans defeated the Serbian army at Kosovo Field, and Serbia was obliged to pay tribute (as of 09/2026, Britannica on the Battle of Kosovo), although both armies lost their rulers in the battle.

Panorama of Kosovo Field: green fields and distant hills

Macedonia, Thessaly, and the Bulgarian principality fell next. By the end of the 14th century, almost all the beyliks of Anatolia had joined the empire, including Janik, Sivas, and Karaman. Some lands joined voluntarily, others after war.

On a map of the 14th-century Balkans, you can see how quickly the border moved. The Ottomans did not only fight: they stationed garrisons and imposed taxes, and that kept the conquered territories under control for a long time.

The Battle of Ankara and the empire's revival

Timur's invasion of Asia Minor shook Ottoman power. In 1402, Sultan Bayezid I lost the Battle of Ankara, and most of Anatolia broke apart into beyliks again (as of 09/2026, Britannica on the Battle of Ankara).

Tamerlane in a chariot routing the Ottomans, antique painting

The empire recovered slowly. First the anti-feudal uprisings were suppressed, then the wars between the sons of Bayezid I came to an end. By the middle of the 15th century, expansion in the Balkans had resumed.

The Ottomans stopped the crusaders twice. In 1444 and 1448, the armies of Sultan Murad II defeated them in the Balkans (as of: 09/2026, chronicle of Ottoman conquests). In roughly forty years after Ankara, the state returned to its former strength.

The fall of Constantinople in 1453

On May 29, 1453, the forces of Mehmed II took Constantinople after a two-month siege (as of: 09/2026, Britannica on the fall of Constantinople). The Eastern Roman Empire ceased to exist, and the city was renamed Istanbul and made the new capital.

Map of Byzantine Constantinople with city walls

After that, the Ottomans established themselves in Europe. In the 1450s-1470s, Serbia lost its independence, and Bosnia, the Morea, the Empire of Trebizond, and Attica were conquered. The Crimean Khanate and Wallachia were made vassals, and Albanian resistance was broken by the end of Mehmed II's reign (as of: 09/2026, data on 15th-century conquests).

1453 became a turning point. It was after this that Europe began to see the Ottomans as a direct threat rather than a distant eastern neighbor.

The peak under Selim I and Suleiman

Selim I ruled from 1512 to 1520, and Suleiman the Lawgiver from 1520 to 1566 (as of: 09/2026, the reign of Suleiman the Lawgiver). During these decades, the empire gained Armenia, Kurdistan, and northern Mesopotamia as far as Mosul.

In the early 16th century, Palestine, Syria, Egypt, the Hejaz, and part of Algeria came under Ottoman control. The fleet became master of almost the entire Mediterranean. In 1521, the Ottomans took Belgrade, and in 1526 they defeated the Hungarians at Mohács (as of: 09/2026, Britannica on the Battle of Mohács).

By the middle of the 16th century, Rhodes, the islands of the Aegean archipelago, Tripolitania, and all of Algeria had passed to the empire (as of: 09/2026, data on the empire's expansion). Its possessions spanned three continents.

Why the empire began to weaken

Ottoman power rested on war and taxes. The conquered peoples carried a heavy burden, and this held back their economies. The preconditions for decline appeared in the same period when the empire was at its peak.

The ruling class was also gradually changing. New feudal landowners were displacing the military fief-holders, and the power of the senior clergy was growing. The sipahis avoided service, and the janissaries started families and took up trades, turning into a separate stratum. The army's fighting qualities declined along with its discipline (as of: 09/2026, section on the empire's decline).

In 1571, the Turkish fleet was defeated at Lepanto, and its military weakness became obvious (as of: 09/2026, Battle of Lepanto 1571). Later, the Ottomans also failed in the war with Russia. The first major territorial losses began in 1699 with the Treaty of Karlowitz. New losses came in 1774.

From empire to republic

After World War I, the Ottoman Empire ceased to exist. A new state emerged on its lands. On October 29, 1923, the Grand National Assembly proclaimed Turkey a republic, and Mustafa Kemal was elected its first president (as of: 09/2026, proclamation of the republic on October 29).

The caliphate was abolished on March 3, 1924, and members of the Ottoman dynasty were expelled from the country (as of: 09/2026, Britannica on Kemal Ataturk). Thus ended an era lasting more than six centuries. Modern Turkey grew not out of the empire, but out of its ruins.

⁉️🤔 Frequently asked questions

When did the Ottoman Empire emerge?

The principality of Osman appeared around 1299 in northwestern Asia Minor (as of: 09/2026, biography of Osman I).

When did Constantinople fall and why does it matter?

The city fell in 1453, and the Ottomans gained direct access to Europe (as of: 09/2026, Britannica on the fall of the city).

Under which sultan did the empire reach its greatest power?

The empire reached its greatest extent under Suleiman the Lawgiver in 1520-1566 (as of: 09/2026, biography of Suleiman).

What caused the decline of the Ottoman Empire?

The main causes: decay of the feudal elite, decline in army discipline, and the defeat at Lepanto in 1571 (as of: 09/2026, destruction of the Ottoman fleet).

When did Turkey become a republic?

On October 29, 1923, with Mustafa Kemal becoming the first president (as of: 09/2026, Britannica on the republic).

In short: key facts about the history of Turkey

The Ottoman Empire went from a beylik in Anatolia to a power spanning three continents and collapsed after World War I. Key dates for you: 1299, 1389, 1402, 1453, 1526, 1571, and 1923 (as of 09/2026, full Ottoman Empire timeline). If you are planning a route through Turkey, keep this sequence handy: it explains why Byzantine walls and Ottoman mosques stand side by side in Istanbul. Save this cheat sheet and come back to it before your trip.

History of the Ottoman Empire: from a principality in Anatolia to a republic