Titus Livius (Livy), The History of Rome, Book 28
Cyrus Evans, Ed.

33. After this harangue he dismissed them, with orders to get themselves in readiness in every respect for marching the next day; when, setting out, he arrived at the river Iberus in ten days. Then crossing the river, he, on the fourth day, pitched his camp within sight of the enemy. [2] Before him was a plain enclosed on all sides by mountains. Into the valley thus formed Scipio ordered some cattle, taken chiefly from the lands of the enemy, to be driven, in order to excite the rapacity of the barbarians, and then [3??] sent some light-armed troops as a protection for them, directing Laelius to charge the enemy from a place of concealment when they were engaged in skirmishing. [4] A mountain which projected conveniently concealed the ambuscade of the cavalry, and the battle began without delay. The Spaniards, as soon as they saw the cattle at a distance, rushed upon them, and the light-armed troops [p. 1207]attacked the Spaniards while occupied with their booty. [5] At first they annoyed each other with missiles; but afterwards, having discharged their light weapons, which were calculated to provoke rather than to decide the contest, they drew their swords, and began to engage foot to foot. [6] The fight between the infantry would have been doubtful, but that the cavalry then came up, and not only, charging them in front, trod down all before them, but some also, riding round by the foot of the hill, presented themselves on their rear, so that they might intercept the greater part of them; and consequently the carnage was greater than usually takes place in light and skirmishing engagements. [7] The resentment of the barbarians was rather inflamed by this adverse battle, than their spirits depressed. Accordingly, that they might not appear cast down, they marched out into the field the following day as soon as it was light. [8] The valley, which was confined, as has been before stated, would not contain all their forces. About two-thirds of their foot and all their cavalry came down to the engagement. The remainder of their infantry they stationed on the declivity of the hill. [9] Scipio, conceiving that the confined nature of the ground would be in his favour, both because the Roman troops were better adapted for fighting in a contracted space than the Spanish, and also because the enemy had come down and formed their line on ground which would not contain all their forces, applied his mind to a new expedient. [10] For he considered that he could not himself cover his flanks with his cavalry, and that those of the enemy which they had led out, together with their infantry, would be unable to act. [11] Accordingly he ordered Laelius to lead the cavalry round by the hills as secretly as possible, and separate, as far as he could, the fight between the cavalry from that between the infantry. [12] He himself drew up the whole body of his infantry against the enemy, placing four cohorts in front, because he could not extend his line further. He commenced the battle without delay, in order that the contest itself might divert the attention of the enemy, and prevent their observing the cavalry which were passing along the hills. [13] Nor were they aware that they had come round before they heard the noise occasioned by the engagement of the cavalry in their rear. [14] Thus there were two battles; two lines of infantry and two bodies of horse being engaged within the space occupied by the plain lengthwise; and that because [p. 1208]it was too narrow to admit of both descriptions of force being engaged in the same lines. [15] When the Spanish infantry could not assist their cavalry, nor their cavalry the infantry, and the infantry, which had rashly engaged in the plain, relying on the assistance of the cavalry, were being cut to pieces, the cavalry themselves also, being surrounded and unable to stand the shock of the enemy's infantry in front, (for by this time their own infantry were completely overthrown,) nor of the cavalry in their rear, after having formed themselves into a circle and defended themselves for a long time, their horses standing still, were all slain to a man. [16] Nor did one person, horse or foot, survive of those who were engaged in the valley. The third part, which stood upon the hill rather to view the contest in security than to take any part of it upon themselves, had both time and space to fly; [17] among whom the princes themselves also fled, having escaped during the confusion, before the army was entirely surrounded.