Though these characters have been fictionalized in multiple stories, including Shakespeare's play "Julius Caesar" and Dante's "Inferno," Brutus (Marcus Junius Brutus) and Cassius (Gaius Cassius Longinus) were real people who lived in ancient Rome during the first century B.C.E. Both of these men were Roman politicians who were appointed to the office of Roman city praetor in 44 B.C.E. by Julius Caesar, who also promoted both men to the office of consul prior to his death. Brutus and Cassius were brothers in law through Cassius' marriage to Junia Tertia, Brutus' half sister.
Brutus and Cassius also became co-conspirators in the death plot to overthrow and murder Julius Caesar. Though these events took place in ancient times and have inspired many fictionalized stories in the intervening years, there is plenty of evidence that these events actually took place, and the real-life existence of Marcus Junius Brutus and Gaius Cassius Longinus is not a disputed fact. Cassius and Brutus were both senators in 44 B.C.E., when Julius Caesar essentially made himself into a perpetual dictator. This act led to the successful murder plot that both Cassius and Brutus helped to plan and carry out. Though some of the fictionalized versions of this event take poetic license with certain details, there is academic consensus on the fact that these two men existed and helped plan Caesar's downfall.