The warrior who united the Mongol tribes and created an empire that was the largest the world has known, has long defied historians.
Though he breached the Great Wall of China, captured Peking, ravaged Afghanistan, Persia and Russia, and between 1237 and 1242 invaded Europe itself, little is left in the way of contemporary records.
History is thus inclined to denigrate or idealize, depending upon the historian. He is a monster, given to grave cruelties, or he is "one of the greatest leaders in the history of the world."