Genghis Khan was the greatest leader in human history.

No one else comes close to conquering as much land as he did. He conquered more land than Alexander the Great, Julius Caesar, Napoleon, and every other warlord in history combined. It's not like he fought a single opposing army and then stopped. No, he conquered every single nation and tribe from China to the Caucuses. He was undefeated and his legacy still endures 800 years later. All the while, he treated his soldiers fairly, granted civility to surrendering enemies and allowed the conquered nations to self govern. His empire was built on strength, but he was a just leader.