There was not just one man. There were many prominent people who took up this cause over the years: the Gracchi brothers, Gaius Marius, Lucius Appuleius Saturninus, Lucius Cornelius Cinna, Publius Clodius Pulcher, and Julius Caesar. During the First Triumvirate, Marcus Licinius Crassus and Pompey the Great sided with the populares, even though they had fought with the opposition party (the optimates) during the civil wars. Pompey then went back to the optimates after the triumvirate.

Julius Saturninus died in 280.

Saturninus of Cagliari died in 304.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

Rome's first consulship was shared by Lucius Junius Brutus and Lucius Tarquinius Collatinus.

It's much easier to say who doesn't die: Marcus Andronicus, Lucius Andronicus and Young Lucius.

The ones who do die are Titus and his children Mutius, Quintus, Martius and Lavinia, Tamora and her sons Chiron, Alarbus and Demetrius, Saturninus and his Brother Bassanius, Aaron (although he actually dies after the play is over, since it ends with him being sentenced to death) and a Nursemaid. Thirteen in all. We're not counting Titus's dead sons that are buried in the first scene of the play.