Mark Antony is the friend and right hand of Caesar, the man who buries him with words and then defeats Brutus and Cassius alongside Octavius. Brutus finds him given to sports, carousing, and company, and for that reason spares him.
In Act I, scene 2, he runs the Lupercal at Caesar's command and, according to Casca, is the one who offers him the crown. In Act II, scene 1, Cassius wants to kill him along with Caesar, but Brutus spares him. In Act III, scene 1, Antony sends a servant to kneel before Brutus, comes in, sees the body, offers himself to death, shakes each conspirator's hand, and obtains permission to speak at the funeral, against Cassius's warning. Alone with the body, he prophesies civil war in Italy and sends word to Octavius.
In the Forum (scene 2), he says he has come to bury Caesar, not to praise him, repeats that Brutus is an honorable man, shows the torn cloak and reads the will, and the crowd goes off to burn the conspirators' houses. In Act IV, scene 1, he marks with Octavius and Lepidus the names of the condemned, including that of his own nephew, and compares Lepidus to an ass that carries gold as far as its master wishes.
At Philippi, he orders Lucilius treated with kindness upon discovering that he is not Brutus. Over Brutus's body (Act V, scene 5), he says Brutus was the noblest of the Romans. After the praise, it is Octavius who gives the orders that close the play.