course of events; after the adjoining nations had been subdued, and by the progressive annexation of conquered territory.  He storms and plunders Carteia, a wealthy city, the capital of that nation; at which the smaller states being dismayed, submitted to his command and to the imposition of a tribute.  His army, triumphant and enriched with booty, was led into winter-quarters to New Carthage.  Having there confirmed the attachment of all his countrymen and allies by a liberal division of the plunder, and by faithfully discharging the arrears of pay, the war was extended, in the beginning of spring, to the Vaccaei.  The cities Hermandica and Arbocala were taken by storm.  Arbocala was defended for a long time by the valour and number of its inhabitants.  Those who escaped from Hermandica joining themselves to the exiles of the Olcades, a nation subdued the preceding summer, excite the Carpetani to arms; and having attacked Hannibal near the river Tagus, on his return from the Vaccaei, they threw into disorder his army encumbered with spoil.  Hannibal avoided an engagement, and having pitched his camp on the bank, as soon as quiet and silence prevailed among the enemy, forded the river; and having removed his rampart so far that the enemy might have room to pass over, resolved to attack them in their passage.  He commanded the cavalry to charge as soon as they should see them advanced into the water.  He drew up the line of his infantry on the bank with forty elephants in front.  The Carpetani, with the addition of the Olcades and Vaccaei amounted to a hundred thousand, an invincible army, were the fight to take place in the open plain.  Being therefore both naturally ferocious and confiding in their numbers; and since they believed that the enemy had retired through fear thinking that victory was only delayed by the intervention of the river, they raise a shout, and in every direction, without the command of any one, dash into the stream, each where it nearest to him.  At the same time, a heavy force of cavalry poured into the river from its opposite bank, and the engagement commenced in the middle of the channel on very unequal terms; for there the foot-soldier, having no secure footing, and scarcely trusting to the ford, could be borne down even by an unarmed horseman, by the mere shock of his horse urged at random; while the horseman, with the command of his body and his weapons, his horse moving steadily even through the middle of the eddies, could maintain the fight either at close quarters or at a distance.  A great number were swallowed up by the current; some being carried by the whirlpools of the stream to the side of the enemy, were trodden down by the elephants; and whilst the last, for whom it was more safe to retreat to their own bank, were collecting together after their various alarms, Hannibal, before they could regain courage after such excessive consternation, having entered the river with his army in a close square, forced them to fly from the bank.  Having then laid waste their territory, he received the submission of the Carpetani also within a few days.  And now all the country beyond the Iberus, excepting that of the Saguntines, was under the power of the Carthaginians.