Julius Caesar is written as a historical tragedy with special import for the Elizabethan period in which Shakespeare writes. As such, Shakespeare takes an extremely serious tone throughout. There is a notable absence of any character who resembles a typical Shakespearean "fool"—a common way in which Shakespeare would inject comic relief into his tragedies. Instead, Shakespeare relays the events of his play in a somber, sober tone. He immerses his characters entirely within their world, and fully invests the audience in their murderous, traitorous plots against each other.
Shakespeare also keeps the tone formal and sophisticated throughout the play. Although the events of Julius Caesar have ramifications for the entire Roman civilization, it is a play about the ruling elite of Rome and their politicking. As such, the tone of the dialogue stays elevated even as the political struggle for power turns to physical violence, murder, and all-out war. Consider, as an example, the formality with which Brutus prepares to kill himself in Act 5, Scene 5:
Countrymen,
My heart doth joy that yet in all my life
I found no man but he was true to me
I shall have glory by this losing day
More than Octavius and Mark Antony
By this vile conquest shall attain unto.
So fare you well at once, for Brutus' tongue
Hath almost ended his life's history.
Night hangs upon mine eyes; my bones would rest,
That have but labored to attain this hour.
In another work by Shakespeare, this level of melodrama could easily be fodder for comedy. Yet Brutus delivers this speech in all seriousness, never once wavering from articulating himself with all the figurative flourishes expected of a Roman senator, and the tragedy of the moment filters through the formality of his tone. For Elizabethan England, Rome was synonymous with "civilization"—and Shakespeare's characters must act the part.
