In 205 BCE, Mago landed in Genua in north-west Italy with the remnants of his Spanish army in an effort to keep the Romans busy to the North and thus hamper indirectly their plans to invade Carthage's hinterland in Africa (modern Tunisia). He was quite successful in reigniting the unrest among various peoples (Ligurians, Gauls, Etruscans) against the Roman dominance. It soon received Gallic and Ligurian reinforcements.

Mago marched his reinforced army towards the lands of Carthage's main Gallic allies in the Po Valley. Rome was forced to concentrate large forces against him which finally resulted in a battle fought in the land of the Insubres (Lombardy). Mago suffered defeat and had to retreat. The strategy to divert the enemy's forces failed as the Roman general Publius Cornelius Scipio laid waste to Africa and wiped out the Carthaginian armies that were sent to destroy the invader. To counter Scipio, the Carthaginian government recalled Mago from Italy (along with his brother Hannibal, who had been in Bruttium until then). However, the remnants of the Carthaginian forces in Cisalpine Gaul continued to harass the Romans for several years after the end of the war.