Marcus Junius Brutus belonged to the illustrious plebeian gens Junia. Its semi-legendary founder was Lucius Junius Brutus, who played a pivotal role during the overthrow of Tarquinius Superbus, the last Roman king, and was afterward one of the two first consuls of the new Roman Republic in 509 BC, taking the opportunity also to have the people swear an oath never to have a king in Rome.