Julius Caesar (100-44 BC)

Few lives in the ancient world moved faster or hit harder than that of Gaius Julius Caesar. He spent nine years subduing Gaul, adding more territory to Rome than any general before him. He crossed the Rubicon with one legion against the orders of the Senate - and in doing so, ended five centuries of republican government. The Rome that existed before Caesar would never exist again.

He won the civil war, declared himself dictator perpetuo, and began remaking the state in his own image. The Senate's answer was twenty-three stab wounds on the floor of a building named after his greatest rival. He was fifty-five years old.

What followed was another seventeen years of civil war, ending only when his adopted son Augustus became the first emperor of Rome. Caesar didn't just conquer territory - he brought a system of government that had endured for half a millennium to its final crisis, and what emerged from the wreckage would last another five hundred years. That is his legacy.