Bayazid I

Bayazid I was an Ottoman sultan who ruled from 1389 to 1402. He was the son of Murad I and inherited the throne on the day of the Battle of Kosovo, where his father was killed. His Turkish epithet Yıldırım (meaning lightning or thunderbolt) reflected the speed with which he moved his armies across different parts of the empire.

His reign is marked by two concurrent developments: the expansion of Ottoman power in the Balkans and the consolidation of Turkish principalities in Anatolia. His rule ended with the Ottoman defeat at the Battle of Ankara in 1402, which caused the empire to fragment for several decades.

Succession

Murad I was killed at the Battle of Kosovo in 1389, fought between Ottoman forces and a Serbian alliance. Bayazid assumed power at the battlefield itself. According to chroniclers, he ordered the execution of his brother Yaqub to ensure that only one person sat on the throne—a custom rooted in earlier Ottoman law governing succession disputes.

The Balkans and the Battle of Nicopolis

Bayazid consolidated Ottoman control over Bulgaria, Macedonia, and parts of Greece, reducing Serbia to a tributary state that provided troops. This expansion alarmed European rulers. In 1396, an allied force led by the Hungarian King Sigismund invaded Bulgaria, comprising knights from France, the German lands, and elsewhere. The force was defeated at Nicopolis (Nikopol, in present-day Bulgaria). This victory enhanced Bayazid's prestige throughout the Islamic world.

Anatolia and the siege of Constantinople

Bayazid absorbed numerous Turkish principalities in Anatolia, including Aydın, Saruhan, Menteşe, Karaman, and others. This rapid expansion alienated displaced rulers who sought outside support. During the same period, he laid repeated siege to Constantinople, the capital of the Byzantine Empire, extracting tributary agreements from Byzantine emperors, though he did not capture the city.

The Battle of Ankara and his death

Bayazid's expansion in Anatolia brought him into conflict with Timur (Tamerlane), who had established a large empire in the east. In July 1402, the armies of both sides met near Ankara. Some of Bayazid's forces, particularly those from the principalities he had conquered, deserted. Bayazid was captured and died in captivity in 1403.

Aftermath

The victory at Ankara triggered a period known as the Fetret Devri (the Interregnum), during which his sons—Süleyman, Isa, Musa, and Muhammad—fought one another for control until Muhammad I reunified the state. Many Anatolian principalities temporarily revived, then were reabsorbed. Constantinople remained in Byzantine hands until 1453.