Metellus Cimber
A conspirator, properly L. Tullus Cimber, but called by Plutarch both 'Tullius Cimber' and 'Metellus Cimber' - the latter being that which Shakespeare took. He supported Caesar and was given Bithynia; however in Act I Scene 3 he is mentioned as a conspirator. Though greeted by Caesar in Act II Scene 2, Metellus gives the signal for the assassination in Act III Scene 1 having begun a suit in the Senate. After the assassination Metellus says only ten further words before leaving the play.
Cinna
A conspirator, properly L. Cornelius Cinna the Younger. Made Praetor by Caesar, though Plutarch records 'in an oration he made had spoken very evill of Caesar' and approved of the assassination. Cassius instructs Cinna in Act I Scene 3 to distribute papers for Brutus to find. In Act II Scene 1 he stands on the fringe of the conspirators in Brutus' orchard. His name is on Artemidorus' list in Act II Scene 3; and after the assassination Cinna is the first to cry out 'Liberty! Freedom! Tyranny is dead!' (III.1.78).
Murellus & Flavius
Two of the five tribunes of the people. They only speak in Act I Scene 1, and are 'put to silence' by Caesar in Act I Scene 2 for despoiling the symbols of regalia that had been placed on Caesar's statue. The ambiguity that surrounds their fate is part of the atmosphere of arbitrariness or tyranny that Shakespeare was trying to create around Caesar's rule.
Political Power and the Constitutional Form of Government
'It must be by his death; and for my part,
I know no personal cause to spurn at him,
But for the general: he would be crown'd.
How that might change his nature, there's the
Question.'
(II.1.10-14)
Thus Brutus justifies assassinating Caesar, overcomes his inner tribulations, with an argument of which the logic is based on what he believes Caesar will become if crowned king: a tyrant. The other conspirators believe they are assassinating Caesar in the name of 'Liberty, freedom and enfranchisement' (III.1.81).
Some critics contend that the story of Julius Caesar is the tragic failure of republicanism to purge Rome of tyranny. The conspirators soon enough find in the aftermath of Caesar, a new form of tyranny is unleashed in the form of the mob. The murder of Cinna (III.2) reveals the irrationality of the mob, a topic many of Shakespeare's characters from his Roman plays at some point focus upon. Shakespeare captures the changeability of the people's fervour in III.2 as they are at first roused by Brutus, and then Mark Antony. Shakespeare's Plebs are not completely devoid of rational thought however. When Antony questions the charge that Caesar was ambitious, citing the consul's refusal of the crown Caska describes in I.2, the Plebs make a reasoned response among themselves:
"1 Plebian:
Methinks there is much reason in his sayings.
2 Plebian:
If thou consider rightly of the matter,
Caesar had great wrong.
3 Plebian:
Has he, masters?
I fear there will a worse come in his place.
4 Plebian:
Mark ye his words? He would not take the crown;
Therefore 'tis not certain he was not ambitious."
(III.2.109-114)
The crowd are, however, malleable to Antony's strategy. His tactfully timed presentation of the will and insistence on upholding the honour of Brutus, Cassius and the other conspirators Antony saves the powerful imagery of Caesar being stabbed until the crowd begin to demand to hear he will. By this stage he has won over their opinions:
"4 Plebian:
They were traitors; honourable men?
...
2 Plebian:
They were villains, murderers. The will, read the will."
(III.2.154-6)
A reader of Machiavelli, Shakespeare, by the evidence of his history plays and tragedies, seems to have been interested in the classically-conceived cycle of political organization and the power of human action as a determinant in this cycle.
Political Murder
Some writers perceived the assassins as the enemies of the ideal state. In Dante's Inferno Brutus and Cassius are shown in the lowest circles of Hell along with Judas Iscariot. Others such as Montaigne have derided the historical Caesar, interpreting his assassination as the proper punishment for tyranny and pride. Typically, Shakespeare follows neither party. The context of conceptions and responses to political murder during Shakespeare's lifetime is of some interest here. The politico-confessional wars on the Continent (specifically the French Wars of Religion and the Dutch Revolt) during the sixteenth century saw the theoretical development of justifications of political murder, by militant strands of both Catholic and Protestant poles.
Elizabeth I's own reign, ridden with potential sources of dynastic and confessional strife, was always wary of the potential for assassination, particularly after the papal bull of excommunication Regnans in excelsis (1570). The threat did not fully dissipate under the early Stuarts - hence the Gunpowder Plot (1605), James I's paranoia of being assassinated (and thus the padded suit he reputedly wore for protection), and the assassination of the Duke of Buckingham, favourite courtier of both James I and Charles I, in 1628. That is not to say by any means that Shakespeare was either advocating or reproving the use of political murder; rather, it was a topical issue, an undercurrent of the political world of the times in which he lived.