Next summer he set out on another expedition against the Vaccaei, in which he took Salmantica by assault, but only succeeded in storming Arbucala, owing to the size of the town and the number and valour of its inhabitants, after a laborious siege. After this he suddenly found himself in a position of very great danger on his return march: being set upon by the Carpesii, the strongest tribe in those parts, who were joined also by neighbouring tribes, incited principally by refugees of the Olcades, but roused also to great wrath by those who escaped from Salmantica. If the Carthaginians had been compelled to give these people regular battle, there can be no doubt that they would have been defeated: but as it was, Hannibal, with admirable skill and caution, slowly retreated until he had put the Tagus between himself and the enemy; and thus giving battle at the crossing of the stream, supported by it and the elephants, of which he had about forty, he gained, to every one’s surprise, a complete success. For when the barbarians attempted to force a crossing at several points of the river at once, the greater number of them were killed as they left the water by the elephants, who marched up and down along the brink of the river and caught them as they were coming out. Many of them also were killed in the river itself by the cavalry, because the horses were better able than the men to stand against the stream, and also because the cavalry were fighting on higher ground than the infantry which they were attacking. At length Hannibal turned the tables on the enemy, and, recrossing the river, attacked and put to flight their whole army, to the number of more than a hundred thousand men. After the defeat of this host, no one south of the Iber rashly ventured to face him except the people of Saguntum. From that town Hannibal tried his best to keep aloof; because, acting on the suggestions and advice of his father Hamilcar, he did not wish to give the Romans an avowed pretext for war until he had thoroughly secured the rest of the country.