10 of History's Most Notorious Traitors

Cassius and Brutus
Allegorical engraving of the assassination of Julius Caesar by a group of nobles including Brutus and Cassius, on the Ides (15th) of March, 44 B.C.E. © Bettmann/CORBIS

Think modern-day politics are a mess? Consider ancient Rome. Cassius, a Roman general who exceled at his job wasn't a big fan of fellow general and Roman senator Julius Caesar.

As Caesar rose to power on a populous wave and declared himself Rome's leader for life, Cassius began to get nervous about Caesar's widespread rule. Eventually, he convinced his friend and fellow Roman general Brutus to feel the same way. Although Brutus was Caesar's friend, too, he was guided by a sense of duty that made him vulnerable to Cassius' emotional manipulation.

After Cassius sent Brutus fake letters outlining the people's support for Caesar's death, Brutus decided to act on a misguided sense of honor. On the Ides of March (March 15), 44 B.C.E., Brutus led a group of senators to stab Caesar to death on the senate floor 23 times, making Cassius and Brutus one of history's first -- and most notorious -- traitorous pairs [source: Vernon].