One important thing to remember is that Shakespeare's play Julius Caesar, while being a historical play that represents some reality, it is not documented history. So, to answer this question the readers must confine their evidence to what occurs in the drama. Here are some reasons that Caesar may have been perceived as a tyrant who deserves to be assassinated:
- Caesar defeats Pompey, a Roman general and triumvir, who is loved by many of the Romans
- He also defeats Pompey's sons
- Caesar kills Flavius and Marullus for "pulling scarves off Caesar's images"
- He acts eager to accept the crown when it is offered to him by Marc Antony and the crowd cheers.
Yet, while Brutus believes that he acts nobly out of love for Rome, his decision to join the conspirators ends in causing Rome to enter into a devastating civil war and be taken over by the second triumvirate of Octavius, Lepidus, and Marc Antony, who is willing to foment the crowd of Rome after the assasination. Antony also is willing to sacrifice his own nephew in his designs for power.
Is Caesar's death an act of justice or murder? Given the meager evidence of Caesar's tyranny in Shakespeare's play, and given the envy of Cassius along with the naivete of Brutus, Caesar's death seems more like murder than an act of justice. Certainly, the play ends as a tragedy, so no good came of the act of assasinating Caesar