be inferred that they would work for a payment whenever their procedence did not come from conquered regions, as apparently Hannibal himself only distinguished among his Hispanics by the form and degree of their allegiance. Thus, in 218, before departing from Cartagena, he sent 16,000 Bastetani, Oretani and Olcade serfs to garrison Carthage in exchange for 15,200 African javelin throwers, seeking to prevent any possible rebellion of any of them due to the distance from their home lands. He also released, before crossing the Pyrenees, many Carpetanians who did not wish to leave Hispania. As a consequence of those moves, Hannibal kept only those with a bond of devotion to him, which would presumably include mercenaries and the most loyal vassals. It is estimated that between 8,000 and 10,000 Hispanics, counting the sum of their many peninsular peoples, reached Italy with Hannibal. The majority of them might have been still alive and serving when he returned to Carthage in 202, proving the reliability that had moved the Punics to hire them. The variety and provenience of the mercenaries is not faithfully recorded, other than Celtiberians, Lusitanians and Balearics, which Hannibal would arrange and use for their particular talents. The first served as heavy cavalry, in contrast to the lighter, skirmishing Numidian cavalry, though they were also entrusted the front lines as infantry in battles like Cannae, where they stood out for their ability to hold the line. Lusitanians are mentioned as having served as mountain troops, possibly playing the role of both skirmishers and heavy cavalry along with Celtiberians. Their combined force, composed of around 2,000 horsemen, was praised by Livy over their more numerous and famous Numidian homologues. Finally, Balearics, ranging between 1,000 and 2,000, excelled as skirmishing infantry, being armed with fibre or sinew slings capable of throwing heavy shot into enemy ranks with devastating effect. Silius Italicus speaks of even more tribes in the army, including Vettones, Gallaecians (combined with the Lusitanians in a single battalion), Cantabrians, Astures, and Vascones, although authors have doubted of such diversity. In any case, Celtiberians and Lusitanians probably were the main bodies of mercenaries, as Hannibal's spiel addressing them before the Battle of Ticinus attests. Other Celtiberians fought against Carthage after their pact with Rome, defeating Hasdrubal Barca's forces in 217 BC. Four years later, they became the first mercenaries employed by Rome, as Publius Cornelius Scipio was forced to hire