Bayezid I

The Battle of Nicopolis, fought on 25 September 1396, was a decisive Ottoman victory over a combined Western European crusading army under Sigismund of Hungary. The last major crusade of the medieval period, its failure cemented Ottoman dominance over the Balkans.

Bayezid I (r. 1389-1402), known as Yildirim, the Thunderbolt, expanded the Ottoman state across the Balkans and Anatolia before his defeat and capture by Timur at the Battle of Ankara in 1402. His reign marks both the zenith of early Ottoman expansion and its fragility.

Murad I (1326-1389) ruled the Ottoman state for some twenty-seven years, moving its capital to Edirne in Europe, reducing the Balkan principalities to vassalage, and developing the institutions of Ottoman government. He was killed at the Battle of Kosovo in 1389.