Nomadic Empires sheds new light on 2,000 years of military history and geopolitics. The Mongol Empire of Genghis-Khan and his heirs, as is well known, was the greatest empire in world history. For 2,000 from the fifth century b.c. to the fifteenth century a.d., the steppe areas of Asia, from the borders of Manchuria to the Black Sea, were a "zone of turbulence," threatening settled peoples from China to Russia and Hungary, including Iran, India,...