Genghis Khan controlled a significant territory.
Genghis Khan . After founding the Empire and being proclaimed `` Genghis Khan '' , he started the Mongol invasions that conquered most of Eurasia . These campaigns were often accompanied by large-scale massacres of the civilian populations -- especially in the Khwarazmian and Western Xia controlled lands . Mongol conquest of Khwarezmia . The Mongol expansion would ultimately culminate in the conquest of virtually all of Asia ( as well as parts of Eastern Europe ) save for Japan , the Mamluk Sultanate of Egypt and most of the Indian subcontinent and Southeast Asia .