Hasdrubal Barca to shift his attention to Africa in 213/212 BC in order to put down this rebellion. Hasdrubal Barca returned to Iberia in late 212 BC, bringing with him 3,000 Numidians under Masinissa, the future king of Numidia. Prelude In 212 BC, the Scipio brothers captured Castulo, a major mining town and the home of Hannibal's wife Imilce. They then wintered at Castulo and Ilugia. The brothers hired 20,000 Celtiberian mercenaries to reinforce their army of 30,000 Romans. The Romans' strength had been reduced by losses sustained against the Carthaginians and Iberian tribes since 218 BC and the need to garrison the main Roman base at Tarraco. Observing that the Carthaginian armies were deployed separately from each other, with Hasdrubal Barca's army near Amtorgis; and, further to the west, Mago Barca with 13,500 men alongside Hasdrubal Gisco's army, the Scipio brothers decided to divide their forces. Publius Scipio led Roman and allied soldiers to attack Mago Barca near Castulo, while Gnaeus Scipio took one-third of the Roman army in Spain and the mercenaries to attack Hasdrubal Barca. This stratagem would lead to two battles, the Battle of Castulo and the Battle of Ilorca, which took place within a few days of each other. Gnaeus Scipio arrived at his objective first. However, Hasdrubal Barca had already ordered the armies of Indibilis and Mandonius (Iberian chieftains friendly to the Carthaginians) and Hasdrubal Gisco to join Mago near Castulo. Hasdrubal Barca held his ground against Gnaeus Scipio, staying within his fortified camp, then managed to bribe the Celtiberian mercenaries to desert Gnaeus Scipio. This led to Hasdrubal's army outnumbering that of Gnaeus Scipio. Hasdrubal bided his time, avoiding any battles with the Romans. Battle of Castulo As Publius Scipio neared Castulo, he was harassed day and night by the Numidian light cavalry under Masinissa. When informed that Indibilis was moving across his line of retreat with 7,500 Iberians, Publius Scipio decided not to face Mago but to attack the Iberian chieftain, fearing that he would be surrounded by Carthaginian forces. Leaving 2,000 soldiers in his camp under the legate Tiberius Fonteus, he marched out that night to launch an attack on the Iberians and, hopefully, evade Masinissa's cavalry. Scipio marched throughout the night and caught Indibilis and his men by surprise in the early morning; and, with a numerical superiority, began to gain the upper hand in the ensuing action. However, the