He was sent in his consulship, 122 BC, against the Allobroges in Gallia Transalpina, because they had received Teutomalius, king of the Salluvii and the enemy of the Romans, and had laid waste to the territory of the Aedui, who were allies of the Romans. In 121 BC, with the assistance of Quintus Fabius Maximus Allobrogicus, he conquered the Allobroges and their ally Vituitus (or "Bituitus"), king of the Arverni, near Vindalium, at the confluence of the Sulga and the Rhodanus; and he won the battle mainly through the terror caused by his elephants. He commemorated his victory by the erection of trophies, and went in procession through the province carried by an elephant. He was honored with a triumph in 120 BC, at the fore of which he paraded the captive Vituitus. He was censor in 115 BC with Caecilius Metellus, and expelled twenty-two persons from the senate. He was also Pontifex. The Via Domitia in Gaul was made by him.