In 137 BC Decimus Junius Brutus also got involved in a campaign against the Vaccaei, who lived to the west of the Celtiberians and not far from Lusitania. The commanders of the Roman province of Hispania Citerior (Nearer Spain, on the east coast of Spain, roughly corresponding to modern Catalonia and Valencia) were fighting in Numantine War (143–133 BC), a rebellion of the Celtiberians who lived to the west of Hispania Citerior. The war was centred on the town of Numantia, which was difficult to besiege, holding out for ten years. In 137 BC the consul Marcus Aemilius Lepidus Porcina was sent to Hispania Citerior to continue the war after the Roman senate rejected a peace treaty made by the other consul for the year, Gaius Hostilius Mancinus. Aemilius did not want to keep his army idle while he was waiting for instructions from Rome and was probably greedy for glory and booty. He falsely accused the Vaccaei of aiding the Celtiberians as an excuse for war. He ravaged the countryside and besieged Pallantia, their main city. He convinced Brutus, who was the commander of Hispania Ulterior and his brother-in-law, to join him. Messengers from the senate arrived and asked why Aemilius sought a new war. They warned him not to continue the attacks on the Vaccaei. Aemilius sent them back to Rome and wrote that it would be dangerous to abandon the war. The siege lasted a long time, during which the Romans run short of food and many men and all the animals died. Aemilius and Brutus eventually had to withdraw, doing so in a very disorderly manner. The Pallantines harassed their flanks and rear and killed many men. When Rome heard of this, Aemilius was recalled, stripped of his command and consulship, and fined. Brutus does not seem to have been punished.