He was sued again in 109 before the Mamilian commission, which investigated possible bribes received by Roman politicians from the Numidian King Jugurtha.
Born before 157, his parents were Marcus Porcius Cato Licinianus and Aemilia Tertia, the youngest daughter of Aemilius Paullus.
[2][3] As a result, Gaius was the nephew of Scipio Aemilianus, the eldest son of Aemilius Paullus and natural brother of his mother.
[10][11] Nothing is known of his activities until his consulship in 114,[12] but Gaius was surely praetor by 117, as the Lex Villia required a three-year wait between holding magistracies.
[22] Gaius was assigned Macedonia as his province, which was normally given to a praetor, but a war against the Scordisci—a Celtic or Illyrian tribe from east Serbia—had broken out and a consul was needed.
[23][24] During the summer Gaius nevertheless suffered a crushing defeat against the Scordisci in northern Thrace, who then could enter Roman territory as far as Delphi and the Adriatic.
[25] The disaster triggered a "religious hysteria" at Rome, with a return to human sacrifice for the last time in Roman history.
He kept his seat in the Senate and remained politically active, as he was sued again in 109 by the Mamilian commission—named after the tribune of the plebs Gaius Mamilius Limetanus.
[36] Officially, this special court was set up to investigate the bribes received by Roman politicians from Jugurtha, the King of Numidia, against whom Rome had been at war since 112.
[44] Gaius' choice shows that he did not expect to be restored, because other exiles often remained closer to Italy in order to lobby for their return, such as Lucius Opimius who settled to Dyrrachium (now Durrës in Albania).