In 1220, the Islamic lands of Central Asia were overrun by the armies of the Mongol invader Genghis Khan (ca. 1155-1227), who laid waste to many civilizations and created an empire that stretched from China to the Caspian Sea. But he failed to destroy the strength of Islam in Central Asia. In fact, by the end of the 13th century, Genghis Khan's descendants had themselves become Muslims. From the death of Genghis Khan in 1227 until the rise of Timur (Tamerlane) in the 1380s, Central Asia went through a period of fragmentation.