In Julius Caesar, Casca is the conspirator who stabs Caesar first.
The assassination occurs in Act III, Scene 1, when the conspirators surround Caesar at the Senate. They approach under the pretext of asking him to recall Publius Cimber, the banished brother of Metellus Cimber. When Caesar refuses, the petition becomes the signal for the attack.
Casca strikes first, followed by the other conspirators. Brutus is the last to stab Caesar, making his participation especially shocking because Caesar trusts him. Shakespeare heightens the emotional impact with Caesar’s famous response, “Et tu, Brute?” before he falls.
A common mix-up is to name Brutus because his stabbing carries the greatest dramatic and symbolic weight. Historically, the assassination involved many conspirators, but Shakespeare’s play clearly identifies Casca as the first attacker. Casca later helps explain the assassination to Cicero and describes the chaotic reaction in Rome.