Titus Livius (Livy), The History of Rome, Book 29
Cyrus Evans, Ed.

2. On the other side, the Roman generals also, Lucius Lentulus and Lucius Manlius Acidinus, lest [2??] by neglecting the first beginnings of the war it should increase in violence, having united their armies, and led their troops through the [p. 1234]Ausetanian territory in a peaceable manner, as though it had been the territory of friends instead of enemies, came to the position of the enemy, and pitched their camp at a distance of three miles from theirs. [3] At first an unsuccessful attempt was made, through ambassadors, to induce them to lay down their arms; then the Spanish cavalry making a sudden attack on the Roman foragers, a body of cavalry was sent to support them from the Roman outposts, when a battle between the cavalry took place with no memorable issue to either side. [4] The next day, at sun-rise, the whole force displayed their line, armed and drawn out for battle, at the distance of about a mile from the Roman camp. [5] The Ausetanians were in the centre, the right wing was occupied by the Ilergetians, the left by some inconsiderable states of Spain. Between the wings and the centre they had left intervals of considerable extent, through which they might send out their cavalry when occasion required. [6] The Romans also, drawing up their army in their usual manner, imitated the enemy in respect only of leaving themselves also intervals between the legions to afford passages for their cavalry. [7] Lentulus, however, concluding that the cavalry could be employed with advantage by those only who should be the first to send them against the enemy's line, thus broken by intervals, ordered Servius Cornelius, a military tribune, to direct the cavalry to ride at full speed into the spaces left in the enemy's line. [8] Lentulus himself, as the battle between the infantry was somewhat unfavourable in its commencement, waited [9??] only until he had brought up from the reserve into the front line the thirteenth legion to support the twelfth legion, which had been posted in the left wing, against the Ilergetians, and which was giving ground. [10] And when the battle was thus placed on an equal footing in that quarter, he came to Lucius Manlius, who was exhorting the troops in the foremost line, and bringing up the reserves in such places as circumstances required, and told him that all was safe in the left wing, and that Cornelius Servius, who had [11??] been sent by him for that purpose, would soon pour round the enemy a storm of cavalry. [12] He had scarcely uttered these words, when the Roman horse, riding into the midst of the enemy, at once threw their line of infantry into disorder, and closed up the passage by which the Spanish cavalry were to advance. [13] The Spaniards, therefore, giving up all thoughts of fighting on [p. 1235]horseback, dismounted and fought on foot. When the Roman generals saw that the ranks of the enemy were in confusion, that they were in a state of trepidation and dismay, their standards moving to and fro, they exhorted and implored their men to charge them while thus discomfited, and not allow them to form their line again. [14] So desperate was their charge that the barbarians could not have withstood the shock, had not the prince Indibilis in person, together with the dismounted cavalry, opposed himself to the enemy before the front rank of the infantry. [15] There an obstinate contest continued for a considerable time; but those who fought round the king, who continued his resistance though almost expiring, and who was afterwards pinned to the earth by a javelin, having at length fallen, overwhelmed with darts, a general flight took place; [16] and the number slain was the greater because the horsemen were prevented from remounting, and because the Romans pressed impetuously upon the discomfited troops; nor did they give over until they had deprived the enemy of their camp. [17] On that day thirteen thousand Spaniards were slain, and about eight hundred captured. Of the Romans and allies there fell a little more than two hundred, and those principally in the left wing. [18] Such of the Spaniards as were beaten out of their camp, or had escaped from the battle, at first dispersed themselves through the country, but afterwards returned each to his own state.