 Several Senators had conspired to assassinate Caesar.Mark Antony, having vaguely learned of the plot the night before from a terrified "liberator" named Servilius Casca, and fearing the worst, went to head Caesar off.The plotters, however, had anticipated this and, fearing that Antony would come to Caesar's aid, had arranged for Trebonius to intercept him just as he approached the portico of the Theatre of Pompey, where the session was to be held, and detain him outside (Plutarch, however, assigns this action of delaying Antony to Brutus Albinus).