Titus Livius (Livy), The History of Rome, Book 41
William A. McDevitte, Sen. Class. Mod. Ex. Schol. A.B.T.C.D., Ed.

26. In Spain, the Celtiberians, (who, since their reduction by Tiberius Gracchus, and their consequent surrender to him, had remained quiet; when Marcus Titinius, the praetor, held the government of that province,) on the arrival of Appius Claudius, resumed their arms, and commenced hostilities by a sudden attack on the Roman camp. [2] It was nearly the first dawn when the sentinels on the rampart, and the men on guard before the gates, descrying the enemy approaching at a distance, shouted “to arms.” Appius Claudius instantly displayed the signal of battle; and, after exhorting the troops, in few words, ordered them to rush out by three gates at once. [3] But they were opposed by the Celtiberians in the very passage; and in consequence, the fight was for some time equal on both sides, as, on account of the narrowness, the Romans could not all come into action in the entrance; [4] then pressing forward on one another, whenever it was possible, they made their way beyond the trenches, so that they were able to extend their line, and form a front equal to the wings of the enemy, by which they were surrounded; and now they [p. 1954]made their onset with such sudden impetuosity, that the Celtiberians could not support the assault. [5] Before the second hour, they were driven from the field; about fifteen thousand were either killed or made prisoners, and thirty-two standards were taken. Their camp, also, was stormed the same day, and a conclusion put to the war; for those who survived the battle fled by different ways, to their several towns, and thenceforth submitted quietly to the Roman government.