Titus Livius (Livy), The History of Rome, Book 29
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

2. The Roman commanders on their part, Lucius Lentulus and Lucius Manlius Acidinus,¹ for fear [2??] the war might grow more serious from neglect of the first hostile acts, likewise united their armies, and leading their soldiers through the Ausetanian territory with restraint on an enemy's soil, as though it [p. 215]were friendly, they reached the place where their² enemies had concentrated and pitched camp three miles away from their camp. At first a vain effort was made through envoys to make them abandon fighting. [3] Then when an attack was suddenly made upon Roman foragers by Spanish horse and from a Roman outpost horsemen were sent to the rescue, there was a cavalry battle with no success for either side worth mentioning. [4] At sunrise on the following day, under arms and drawn up, all of them displayed their battle-line at a distance of about a mile from the Roman camp. [5] The Ausetani were in the centre; of the wings the Ilergetes occupied the right, unimportant Spanish tribes the left. Between the wings and the centre they had made spaces broad enough to send the cavalry through when the time came. [6] And the Romans, having drawn up their army in the customary fashion, imitated this feature only of the enemy's line, that they likewise left broad spaces between the legions for the passage of cavalry. [7] But Lentulus thought that whichever side should first send its cavalry out into the enemy's line with its gaping intervals would use its cavalry to advantage. [8] He therefore ordered Servius Cornelius, a tribune of the soldiers, to command his cavalry to give their horses free rein through the broad openings in the battle-line of the enemy. [9] Lentulus himself, after the infantry battle had begun without success, delayed only long enough to bring up the thirteenth legion from the reserves into the front line to support the twelfth legion, which had been placed on the left wing facing the Ilergetes and was giving way. [10] Now that the battle was evenly balanced there, he came up to Lucius Manlius, who [p. 217]was in the foremost ranks, encouraging the men³ and bringing up reserves to such positions as the case required. [11] He informed him that all was secured on the left wing; that he had already sent Servius Cornelius to surround the enemy with a whirlwind attack of cavalry.

[12] Scarcely had Lentulus said this when the Roman horse, charging into the midst of the enemy, threw the infantry lines into confusion and at the same time closed for the Spanish cavalry the route by which they might launch their attack. [13] Accordingly the Spaniards gave up the cavalry battle and dismounted. The Roman generals, on seeing the broken ranks of the enemy, and their fright and alarm and the wavering standards, exhorted and implored their soldiers to attack the discouraged enemy and not allow the line to re-form. [14] The barbarians would have failed to withstand so impetuous an attack, had not even their prince, Indibilis, exposed himself with the dismounted cavalry in front of the first units of the infantry. At that point a fierce battle continued for some time. [15] Finally, when those who kept on fighting round the prince, who resisted though half-dead, but was pinned to the ground by a javelin, were overwhelmed by missile weapons and fell, at that moment began a flight pell-mell. [16] Greater numbers were slain because the horsemen had left no room to mount their horses, and because the Romans made a spirited attack upon the terrified. And they did not withdraw until they had routed the enemy out of his camp as well. [17] Thirteen thousand Spaniards were slain that day, about one thousand eight hundred captured. Of the Romans and their allies little more than two [p. 219]hundred fell, mainly on the left wing. [18] Those of the⁴ Spaniards who were driven out of their camp or had escaped from the battle scattered at first over the country and then returned to their respective communities.