Timur was one of the most powerful Central Asian rulers since Genghis Khan. By long and relentless fighting, he sought to rebuild the Mongol Empire of his predecessors. Timur had conquered Georgia and Azerbaijan in 1390 and Syria in 1399 after defeating the Mamluks, expanding his empire to the borders of the Ottoman Empire. The two powers soon came into direct conflict. Bayezid demanded tribute from one of the Anatolian Beyliks who had pledged loyalty to Timur and threatened to invade. Timur interpreted this action as an insult to himself and in 1400 sacked the Ottoman city of Sebaste (modern Sivas). In 1402, the Ottomans campaigned in Europe, trying to conquer Hungary. Timur, a wise and educated military leader, found it as a proper moment to attack and destroy the Ottoman empire. Beyazid