In the play "Julius Caesar" by William Shakespeare, Brutus fits the definition of a tragic hero. Marc Antony describes Brutus as the noblest Roman even after Brutus kills Caesar. Since Brutus did not kill Caesar out of envy or a desire for power, Brutus's participation in the assassination was considered honorable.
The tragic flaw that eventually led to Brutus's downfall was his rigid idealism. An example of this is when Brutus and the other officials are planning Caesar's assassination, and one of the officials asks those present to swear to keep their plot a secret. Brutus responds that he does not need to swear as he trusts all of the officials. The irony is that the officials wrote the letter, posing as a simple Roman villager, that convinced Brutus that killing Caesar was necessary.
Brutus's rigid idealism was also the reason why he was the hero of the play. His reputation as an honorable man who always acts for the betterment of the Roman people endears his character to the audience. The tragedy of Brutus's death arises from the fact that the heroic qualities of the character were the reason for his eventual demise. In the end, Brutus kills himself in heroic fashion by hurling himself upon his own sword as he would rather commit suicide than be conquered.