Mago presented the golden rings of Roman equites fallen at Cannae to the Carthaginian Senate, requesting reinforcements for Hannibal at the end of his speech.
[5] Mago's army, numbering 12,000 infantry, 1,500 cavalry, 20 war elephants, with 1,000 talents was raised slowly, perhaps due to anti Barcid intrigues.
[6] However, when the news of the disastrous Battle of Dertosa reached Carthage, Mago and his army were sent to Hispania (the Iberian Peninsula) as reinforcements for Hasdrubal instead.
Mago, in a cavalry ambush of Publius Cornelius Scipio, killed 2,000 Romans near Akra Leuke in 214 BC, and also aided in keeping the Hispanic tribes loyal to Carthage.
The situation was favorable enough, as in 212 BC, Hasdrubal managed to cross over to Africa with an army to crush the rebellion of Syphax, king of Numidian tribes, without the Scipios causing any disruptions in Hispania.
The coordination of the three Carthaginian armies was crucial in defeating and killing the Scipio brothers and destroying most of the Roman forces in Hispania in the battles that followed.
Publius Cornelius Scipio the Younger, exploiting the lack of coordination between the Carthaginian generals, and the scattered location of their armies, ended up taking Cartagena in a daring expedition in 209 BC.
In 208 BC, after the Battle of Baecula, Hasdrubal left Hispania to invade Italy and bring reinforcements to his brother Hannibal, who was operating in Lucania.
Mago moved with his army to the area between the Tagus and Douro rivers in a recruiting mission of Spanish mercenaries with Hanno, a newly arrived general.
Their mission was successful, as they gathered large masses of Spanish fighters, among them Cantabrians led by Larus, but they divided the army into two camps and relaxed their vigilance.
After suffering defeat at the Battle of Ilipa in 206 BC, Hasdrubal Gisco returned to Africa and Mago retreated to Gades with the remnants of his army.
His deputy, another Hanno, was defeated by L. Marcius at the Battle of the Guadalquivir, and Mago was unable to take advantage of the rebellion of Hispanic tribes under Indibilis or the mutiny of the Roman troops at Sucro in 206 BC.
Mago managed to capture Genoa, and he held control of northern Italy for nearly three years, warring with the mountain tribes and gathering troops.
Mago and his army sailed from Italy in 202 BC under the escort of the Punic fleet, and was unmolested by the Roman navy as he made for Africa.
According to Cornelius Nepos, however, Mago survived the war and stayed with his brother Hannibal for several years, until the Carthaginians ordered his arrest around 193 BC.