Flavius, a soldier, and Murellus, a tribune, ask a group of commoners why they are celebrating. A cobbler tells them they are celebrating Caesar’s triumph over Pompey. Murellus chastises them for their hypocrisy; not long ago, the plebeians loved and celebrated Pompey. Flavius and Murellus break up the celebrations, telling the citizens to pray to the gods against their ingratitude. They set off to the temple of Jupiter to remove any adornments left by Caesar’s followers. 

Julius Caesar, his wife Calpurnia, and Mark Antony enter the town square in preparation to celebrate Lupercalia. Caesar asks Mark Antony, who is running in the festival, to touch Calpurnia as he passes; he says it is a remedy for sterility. A soothsayer in the crowd bids Caesar to “[b]eware the ides of March” (I.2.19). Caesar ignores the warning. Everyone leaves except senators Decius Brutus and Caius Cassius.

Cassius notes that Brutus seems less friendly lately. Brutus admits that he feels conflicted. Cassius uses this as an opportunity to discuss Caesar. They hear a flourish of trumpets; Brutus says, “What means this shouting? I do fear the people/ Choose Caesar for king” (I.2.81). Although he loves Caesar, he values the Roman Republic and weighs honor equally with death.