Bayezid took with him an army composed primarily of Balkan vassal troops, including Serbs led by Lazarevic. He soon faced an invasion of Anatolia by the Central Asian ruler Timur Lenk. Around 1400, Timur entered the Middle East. Timur Lenk pillaged a few villages in eastern Anatolia and commenced the conflict with the Ottoman Empire. In August, 1400, Timur and his horde burned the town of Sivas to the ground and advanced into the mainland. Their armies met outside of Ankara, at the Battle of Ankara, in 1402. The Ottomans were routed and Bayezid was taken prisoner, later dying in captivity. A civil war, lasting from 1402 to 1413, broke out among Bayezid's surviving sons. Known in Ottoman history as the Interregnum, that struggle temporarily halted active Ottoman expansion in the Balkans.