An unknown number of Carthaginian citizens were incorporated into this army. In early 240 BC Hanno was defeated while attempting to raise the siege of Utica at the Battle of Utica. For the rest of the year Hanno skirmished with the rebel force, repeatedly missing opportunities to bring it to battle or to place it at a disadvantage; the military historian Nigel Bagnall writes of Hanno's "incompetence as a field commander". At some point during 240 BC the Carthaginians raised another army, of approximately 10,000. It included deserters from the rebels, newly hired mercenaries, citizen militia, 2,000 cavalry, and 70 elephants, and was placed under the command of Hamilcar Barca, who had previously led the Carthaginian forces on Sicily. Hamilcar led this force out from Carthage and a rebel army of 25,000 under Spendius moved to attack it in the Battle of the Bagradas River. After a complex battle, the Carthaginians routed the rebels, who suffered losses of 8,000 men. Hamilcar was appointed joint commander of the Carthaginian army, alongside Hanno, but there was no cooperation between the two. While Hanno manoeuvred against Mathos to the north near Hippo, Hamilcar confronted several towns and cities that had gone over to the rebels, bringing them back to Carthaginian allegiance with varying mixtures of diplomacy and force. He was shadowed by a superior-sized rebel force under Spendius, assisted by the experienced Gallic commander Autaritus. Spendius felt unable to face Hamilcar's cavalry and elephants in open battle and so stayed on higher and broken ground, where much of the effect of the cavalry and elephants would have been nullified. From here the rebels harried the Carthaginian foragers and scouts. A war of attrition worked for the rebels, with their superior numbers they could withstand more losses than the Carthaginians. Spendius probably also awaited reinforcements and a favourable situation in which to engage Hamilcar's army. It is not known what measures Hamilcar employed to counter the harassment tactics of Spendius, or the exact route Hamilcar followed after his victory over the rebels at the Bagradas River. Hamilcar's army by this time consisted of between 10,000 and 15,000 men, as well as his elephants. Spendius' force totalled some 20,000–25,000 men: half or more were freshly recruited Libyans, 8,000 were veterans from Sicilymany of them Gauls, under Autaritusand there were 2,000 Numidian cavalry. Engagement Hamilcar marched a long distance to the east during this campaign, but