Beyazid I, also known as Beyazid the Thunderbolt, was an important Ottoman Sultan who ruled from 1389 to 1402. He is best known for his military conquests and efforts to expand the Ottoman Empire. Under his leadership, the empire grew significantly, particularly in the Balkans, where he captured key territories and strengthened Ottoman power. Beyazid I faced many challenges during his reign, including conflicts with the Mongol Empire and internal strife. His most notable defeat came at the hands of Timur, a powerful Central Asian conqueror, in 1402. This defeat led to a temporary setback for the Ottoman Empire, but Beyazid's legacy as a formidable leader remains significant in history.