Genghis Khan

Born Temüjin, son of a minor steppe chieftain murdered when he was nine. By forty he had unified every nomadic tribe between the Altai mountains and the Khingan range; over the next twenty-one years he conquered the Tangut, Jin, and Khwarezmian empires, creating in one generation the largest contiguous land empire in human history. His campaigns are credibly estimated to have killed forty million people. He died on campaign against the Western Xia and was buried in an unmarked grave whose location is still unknown.