21. Julius Caesar
The first Roman emperor, Julius Caesar transformed Rome from a republic into an empire. He expanded its military might while promoting virtue among Roman citizens, believing that the realm would be upheld through Roman families. He usurped for himself many of the powers and privileges that had previously belonged to the Senate, and along the way, he earned himself a good many enemies. Even his friends turned on him, and they stabbed him to death on the Ides of March.