hiring them as a personal guard. Later, in 368, his son Dionysius II sent a contingent of those Celts and Iberians to the Theban–Spartan War in order to assist the Spartans in the siege of Corinth, which they did with great effectivity. They also captured the territory of Sicyon before sailing back to Sicily. When Plato visited his apprentice Dionysius II in 361 BC, he witnessed a brief rebellion by the king's mercenaries due to his attempts to reduce their payment. They marched towards the acropolis chanting their war paean, scaring Dionysius II so much that he relented and gave them even more than they reclaimed. Balearic slingers were also present in the Carthaginian side in the 311 Battle of the Himera River. 3rd century BC In 274 BC, Hiero II of Syracuse ended the traditional mercenary presence in Sicily in order to prevent more mutinies. He pitted them against the Mamertines, a body of Italian marauders, in the river Cyamosorus near the city of Centuripa, and then left them to their fate. Withholding his own citizen troops in order to stack the odds against the mercenaries, Hiero saw them being defeated and decimated. However, it is likely he continued hiring Hispanic mercenaries anyway, as Livy mentions them as auxiliars in the army of his grandson Hieronymus. Carthaginian peninsular mercenaries did not return to Sicily until the First Punic War in 264, this time in the army commanded by Hanno. When Carthage lost the war the Hispanics were amongst the mercenaries transported to Africa to be paid off and discharged. There the foreign warriors rebelled against the Carthaginians when the latter were unable to pay their emolument, due to the economic sanctions imposed by Rome. This led to the Mercenary War and the destruction of the rebels by loyal Carthaginian forces led by Hamilcar Barca. It would be in the Second Punic War, though, that Iberian peninsulars become a factor again, given that Hispania was the main front of the war. Upon Hamilcar Barca's arrival to Hispania in 237 BC, he succeeded at conquering multiple Hispanic tribes and drawing reinforcements from them, employing alliances, payment and hostages depending on the case. His son Hannibal continued his effort after his death with plans to lead an expeditionary army to Italy. As mentioned earlier, in this case it is again difficult to differentiate between true mercenaries and conscripted vassals: it can only