Flavius Silva

 was the leader of a Roman legion during the siege of Masada. He met the First Doctor during the siege, making him an advisor. Silva planned to attack the Jewish rebels at Masada, killing most of the rebels. The Doctor asked him to spare his two "spies" in the Jewish camp, Ian Chesterton and Barbara Wright. When he finally breached the walls, he found all but two of the rebels had collectively killed themselves. (PROSE: The Last Days)