Marcus Junius Brutus was one of the assassins of Julius Caesar.
In Shakespeare's play Julius Caesar, Cassius says to Brutus: "The fault, dear Brutus, is not in our stars, but in ourselves, that we are underlings". Elim Garak thought it absurd that Caesar would not suspect Brutus of betrayal, While Will Riker thought it ironic that Brutus and Cassius murdered a man they both admired. (DS9 episode: "Improbable Cause", TNG novel: Imzadi)