- On February 15, the Feast of Lupercal, the people of Rome celebrate Caesar’s victory over Pompey in a civil war.
- Marullus and Flavius, two government officials who support Pompey, attempt to discourage celebrating workers.
- On the same day, Caesar attends the traditional race at the festival of Lupercal and receives a warning from a soothsayer to “beware the ides of March”. (The middle of March –March 15) Caesar brushes off this warning.
- After Caesar leaves, Cassius tries to persuade Brutus to turn against Caesar.
- Caesar returns and mentions to Antony his distrust of Cassius.
- Casca tells Brutus and Cassius the details of Caesar’s rejection of a crown offered to him by the people of Rome. Brutus and Cassius agree to meet again to discuss Caesar. In his soliloquy, Cassius tells of his plan to manipulate Brutus by sending him letters from the people of Rome speaking of their admiration for him.
On the night of March 14, a terrible storm brings different reactions:
- Casca believes that the storm and other omens mean that the future will bring evil
- Cassius believes that these same signs mean that Caesar must be stopped.
The two men agree that Caesar must not be allowed to continue to rule, and when Cinna joins them, they plot to convince Brutus to join their conspiracy.
- Shortly before dawn on March 15 (ides of March), Brutus walks in his garden unable to sleep, brooding over the decision he must make. His soliloquy indicates he is extremely conflicted.
- He receives an anonymous letter (from Cassius) urging him to act on Rome’s behalf.
- Cassius and the conspirators visit Brutus and finalise their plans for the assassination.
- Brutus’ wife, Portia, urges him to reveal his secret to her. (As to why he has become so upset lately)
- Shortly after dawn on March 15, Caesar and his wife Calpurnia awake due to the storm. Caesar intends to go to the Capitol, but Calpurnia urges him to stay home because of the many threatening omens. Caesar agrees to stay home for her sake.
- Decius, one of the conspirators, convinces Caesar that he must not seem to be afraid of his wife’s superstitions. Thus, he tricks Caesar into going to the Capitol.
- The other conspirators meet at Caesar’s house to make sure he does not decide to stay at home.
- Artemidorus, one of Caesar’s supporters, has learned about the plot against Caesar.
- He reads a letter of warning he has written to Caesar and then waits in the street for Caesar to pass so that he may give it to him.