Marcus Brutus, a noble Roman senator, conspires with other senators including Cassius to assassinate Julius Caesar, whom they believe wants to make himself king and threaten Roman republican rule. On the Ides of March, Brutus and the other conspirators kill Caesar. However, Marc Antony, Caesar's friend, turns the public against the conspirators with a moving funeral speech praising Caesar, leading to civil war between the two factions. In the end, Brutus and Cassius are defeated at the Battle of Philippi, plunging Rome into further conflict.