The play begins with Julius Caesar’s triumphant return to Rome after defeating his enemies in Spain. But the festive mood doesn’t last long as the conversations between Flavius and Marullus hint at conspiracies against Caesar.

Though Julius Caesar is warned to be cautious of the “ides of March” by a soothsayer, he doesn’t pay them much heed and leaves to participate in games to celebrate the feast of Lupercal. After his departure, only Brutus and Cassius remain. Brutus has been Caesar's friend for a long time, but that doesn't stop him from not being opposed to an uprising against Caesar that Cassius hints at.