I believe your question refers to Brutus in Shakespeare's Julius Caesar and I have moved it accordingly.
Brutus is one of the major characters in Julius Caesar. He is a Roman aristocrat who happens to be a good friend of Julius Caesar but is persuaded by another Roman aristocrat, Cassius, to become the leader of a conspiracy to assassinate Caesar to prevent him from becoming a king or emperor, as he evidently is scheming to do.
A complete description of Brutus is to be found in eNotes Study Guide under the topic of "Character Analysis." It includes this passage:
Brutus is a Roman nobleman who plays a prominent role in the conspiracy against Caesar. The primary issues surrounding Brutus's character are his idealism and devotion to the principle of republicanism, his political judgment, his motives for joining the conspiracy, and his role as a tragic hero. Brutus is typically viewed as a noble man, although some argue that he is flawed in his philosophical commitment to principle. It has also been suggested that Brutus unwittingly creates the chaos that descends upon Rome after the assassination.
Shakespeare based his play on an English translation of three chapters in Plutarch's Parallel Lives, using "The Life of Julius Caesar," "The Life of Brutus," and the "Life of Antony" from that collection of biographies. Shakespeare, however, leaves out most of "the chaos that descends upon Rome [and also upon Italy] after the assassination."
Brutus is the most sympathetic character in the play, and much of the play features his point of view. As in actual history, Brutus and Cassius were successful in their assassination plot but were later defeated on the battlefield at Philippi by Marc Antony and Octavius. Antony respected Brutus and grieved at his death. As in actual history, as recounted by Plutarch, Brutus commits suicide on the field of battle after he and Cassius are both defeated. Shakespeare has Antony speaking the following words:
This was the noblest Roman of them all:
All the conspirators save only he
Did that they did in envy of great Caesar;
He only, in a general honest thought
And common good to all, made one of them.
His life was gentle, and the elements
So mix'd in him that Nature might stand up
And say to all the world 'This was a man!'