Genghis Khan
Genghis Khan, was the founder and first Great Khan (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 Empire and being proclaimed Genghis Khan, he launched the Mongol invasions that conquered most of Eurasia, reaching as far west as Poland and the Levant in the Middle East. Campaigns initiated in his lifetime include those against the Qara Khitai, Khwarezmia, and the Western Xia and Jin dynasties, and raids into Medieval Georgia, the Kievan Rus', and Volga Bulgaria. These campaigns were often accompanied by large-scale massacres of the civilian populations, especially in the Khwarazmian- and Western Xia–controlled lands. Because of this brutality, which left millions dead, he is considered by many to have been a brutal ruler. By the end of his life, the Mongol Empire occupied a substantial portion of Central Asia and China. Due to his exceptional military successes, Genghis Khan is often considered to be the greatest conqueror of all time.