Genghis Khan: 13th-Century Mongolian Tyrant

Genghis Khan set out to conquer the world.  His Mongol warriors were the fastest, most efficient army on earth.  They destroyed cities, burned villages, and turned farmers into homeless wanderers.
 
Rumors about the Mongol leader's ruthlessness followed him from East Asia to eastern Europe.  But Genghis Khan did not need rumors to make his enemies fear him.