Marcus Brutus
The moral center of the conspiracy and its biggest liability. Brutus joins because he believes it is right, not because he hates Caesar. His honorable reputation is what the conspiracy needs, but his idealism drives every decision that destroys it.
Gaius Cassius
The architect of the plot. Cassius is shrewd, envious of Caesar, and a skilled manipulator. He knows Brutus better than Brutus knows himself and uses that knowledge to recruit him. Cassius is usually right about strategy and usually overruled by Brutus.
Julius Caesar
The target of the conspiracy, but a more complex figure than a simple tyrant. Caesar is proud, superstitious, and easily flattered. He ignores warnings and lets vanity override caution. He is more powerful dead than alive.
Mark Antony
Caesar's loyal ally and the play's most effective political operator. Antony appears harmless to the conspirators, then dismantles them with a single speech. He understands people and uses grief as a weapon.
Portia
Brutus's wife. She knows something is wrong and demands to be trusted with the secret. Her death before Philippi is one of the few moments where Brutus's emotional life breaks through. She represents what Brutus sacrifices for his political ideals.
Calphurnia
Caesar's wife. She has nightmares about his death and begs him to stay home. Caesar almost listens. Her warning is the last real chance Caesar has to survive, and Decius talks him out of taking it.
Octavius Caesar
Caesar's heir and Antony's co-commander. Octavius is young but already asserting himself against Antony's authority. He ends the play in control of Rome, which is exactly the outcome the conspirators were trying to prevent.
Decius Brutus
One of the conspirators. His main function is getting Caesar to the Senate on the day of the assassination by reinterpreting Calpurnia's dream and appealing to Caesar's pride.
Casca
A blunt, cynical senator who is the first to stab Caesar. He reports events to Cassius and Brutus with dry sarcasm and is one of the more realistic voices in the conspiracy.