What is the climax of Julius Caesar?why?

"Cius’s death (V.iii), upon ordering his servant, Pindarus, to stab him, marks the point at which it becomes clear that the murdered Caesar has been avenged, and that Cius, Brutus, and the other conspirators have lost in their attempt to keep Rome a republic rather than an empire. Ironically, the conspirators’ defeat is not yet as certain as Cius believes, but his death helps bring about defeat for his side."