Mongolia: Genghis Khan (r.1206-1227), 1st Khagan of the Mongol Empire.

Genghis Khan (1162-1227), born Borjigin Temujin, was the founder, Khan (ruler) and Khagan (emperor) of the Mongol Empire, which became the largest contiguous empire in history after his death. He came to power by uniting many of the nomadic tribes of northeast Asia. After founding the Mongol Empire and being proclaimed 'Genghis Khan', he began the Mongol invasions that would ultimately result in the conquest of most of Eurasia. These included raids or invasions of the Kara-Khitan Khanate, Caucasus, Khwarezmid Empire, Western Xia and Jin dynasties. These campaigns were often accompanied by wholesale massacres of the civilian populations - especially in Khwarezmia. By the end of his life, the Mongol Empire occupied a substantial portion of Central Asia and China.