In 77 BC, when Lepidus had left for his proconsular command (he was allocated the provinces of Cisalpine and Transalpine Gaul to the north of Italy), his political opponents moved against him. He was recalled from his proconsular command. When he refused to return they declared him an enemy of the state and passed a Consultum Ultimum (a.k.a. the Ultimate Decree) which called on the interrex Appius Claudius and the proconsul Quintus Lutatius Catulus to take necessary measures to preserve public safety. They persuaded Pompey, who had several legions' worth of veterans in Picenum (in the north-east of Italy) ready to take up arms at his command, to join their cause. Pompey, invested as a legate with propraetorial powers, quickly recruited an army from among his veterans and threatened Lepidus, who had marched his army to Rome, from the north. Catulus, who had recruited an army at Rome, now took on Lepidus directly defeating him in a battle north of Rome. Meanwhile, Pompey had penned up Marcus Junius Brutus, one of Lepidus's commanders, in Mutina. Pompey then marched against Lepidus' rear catching him near Cosa, but although he defeated him Lepidus was still able to embark part of his army and retreat to Sardinia.