If Caesar is going to be called the antagonist of this play, it’s only because he moves the action along in constant opposition to the will of the protagonist, Antony. Again, all of this is arguable, but it is clear that Caesar makes some pretty nasty moves to get Antony going. He calls Antony back from Alexandria to fight Pompey, and again challenges him publicly to start the wars between them. Still, Caesar did have some legit complaints: Antony did drop the ball on being one of three leaders in a globe-spanning enterprise. Still, for the purposes of this play as Shakespeare presents it, Caesar is a nasty guy. He breaks truce with Pompey, slanders and unseats Lepidus, and generally is a little punk when compared to Antony’s long history as a soldier (Caesar is twenty years younger than Antony). He doesn’t know his place, but he’s lucky, which sets him up in stark contrast to Antony, a man who’s down on his fortunes.