Marcus Licinius Crassus

 was a proconsul in the Roman Army, trying to re-capture rebelling slaves led by Spartacus. In 71 BC, the Second Doctor ended up in Crassus' camp and distracted him by suggesting he build a wall across Italy, thereby allowing Pompey to end the war and become the most powerful man in the Roman Republic.

Crassus was long dead by 48 BC. (PROSE: The Slave War)