He betrayed Quintus Sertorius, and was executed by Pompey the Great. Perpenna belonged to the populares faction, led by Gaius Marius and Lucius Cornelius Cinna. After Lucius Cornelius Sulla defeated the populares faction in Italy and became Dictator of Rome, Perpenna fled with a substantial sum of money and an army.
He took refuge in Hispania (the Iberian Peninsula, comprising modern Spain and Portugal), where he was determined to wage war against Quintus Caecilius Metellus Pius on his own, despite the fact that Sertorius was already present in the province and was more or less ruling lieutenant
However, Perpenna"s soldiers were dissatisfied with his leadership, and when they learned that Pompey was crossing the Pyrenees, they demanded that Perpenna take them to Sertorius, or they would abandon him to Pompey"s mercies while they took themselves to Sertorius. Perpenna yielded to the demands of the legions, and handed them over to Sertorius.
This was not done with good will, and Perpenna, conscious of his noble bloodline and wealth, viewed the entire affair as a humiliation. Sertorius" string of victories soon began to inspire discontent in the Roman nobles and senators that made up the higher classes of his domain.
These people grew jealous of Sertorius" power, and Perpenna, aspiring to take Sertorius" place, encouraged that jealousy for his own ends.
They took to damaging Sertorius" measures for victory, or oppressing the local Iberian tribes in his name. This stirred discontent and revolt in the tribes, which resulted in a cycle of oppression and revolt, with Sertorius none the wiser as to who was creating such mischief. Perpenna then proceeded to invite Sertorius to a feast to celebrate a supposed victory.
While under most circumstances, any festivities to which Sertorius was invited were conducted with great propriety, this particular feast was vulgar, designed to offend the skillful general.
Disgusted, Sertorius changed his posture on the couch, intent on ignoring them all. At this, Perpenna gave the signal to his minions, and they murdered the unsuspecting Sertorius on the spot.
Upon learning of the death of Sertorius, the Iberian tribes sent ambassadors to Pompey and surrendered to him. Perpenna managed to retain control of the Roman renegades who had followed Sertorius, and engaged Pompey in battle.
Crushed, he attempted to plead for his life, offering to give Pompey all of Sertorius" papers and letters, which would document contacts with the highest levels of Roman government and society.
Pompey indicated he would accept the papers, and when they had all been gathered together, he burned them, averting the possibility of another civil war. He then executed Perpenna and all of the men who had murdered Sertorius. The names Perperna and Perpenna are attested for this nomen gentile (of Etruscan origin), but Perperna is more frequent and the form used in the most reliable inscriptions, followed by the prosopographical scholarship (eg Broughton).