Titus Livius (Livy), The History of Rome, Book 34
Cyrus Evans, Ed.

14. At midnight, after having given his attention to the auspices, he began his march, that he might take possession of such ground as he chose, before the enemy should observe him. Having led his troops beyond their camp, he formed them in order of battle, and at the first light sent three cohorts close to their very ramparts. [2] The barbarians, surprised at the Romans appearing on their rear, ran hastily to arms. [3] In the mean time, the consul observed to his men, “Soldiers, you have no room for hope, but in your own courage; and I have, purposely, taken care that it should be so. [4] The enemy are between us and our camp; behind us is an enemy's country. What is most honourable, is likewise safest; namely, to place all our hopes in our own valour.” He then ordered the cohorts to retreat, in order to draw out the barbarians by the appearance of flight. [5] Every thing happened as he had expected. The enemy, thinking that the Romans retired through fear, rushed out of the gate, and filled the whole space between their own camp and the line of their adversaries. [6] While they were hastily marshalling their troops, the consul, who had all his in readiness, and in regular array, attacked them when in disorder. He caused the cavalry from [p. 1506]both wings to advance first to the charge: but those on the right were immediately repulsed, and, retiring in disorder, spread confusion among the infantry also. [7] On seeing this, the consul ordered two chosen cohorts to march round the right flank of the enemy, and show themselves on their rear, before the two lines of infantry could close. The alarm which this gave the enemy, which had been thrown to a disadvantage by the cowardice of the Roman horse, restored the fight to an equality. [8] But such a panic had taken possession of both the cavalry and infantry of the right wing, that the consul laid hold of several with his own hand, and turned them about with their faces to the enemy. [9] As long as the fight was carried on with missile weapons, success was doubtful; and on the right wing, where the disorder and flight had first began, the Romans with difficulty kept their ground. [10] On their left wing, the barbarians were both hard pressed in in front; and looked back, with timidity, at the cohorts that threatened their rear. But when, after discharging their iron darts and large javelins, they drew their swords, the battle, in a manner, began anew. [11] They were no longer wounded by random blows from a distance, but, closing foot to foot, placed all their hope in courage and strength.