Titus Livius (Livy), The History of Rome, Book 32
Evan T. Sage, Ph.D. Professor of Latin and Head of the Department of Classics in the University of Pittsburgh, Ed.

12. Meanwhile, on the third day, when the Romans had sent up the smoke-signal that they had reached and were holding the height which they had sought, then in earnest the consul formed his army in three columns and marched with the flower of his troops up the middle of the valley and hurled his right and left wings against the camp; [2] the enemy came to meet him with no less vigour. [3] And while, carried forward by their desire to fight, they were struggling outside the breastworks, the Roman army enjoyed no small advantage in courage and skill and character of weapons; but after the [p. 187]king's troops, when many had been wounded and¹ killed, retired to positions strengthened by art or strong by nature, the danger recoiled upon the Romans, who pushed forward impetuously over unfavourable ground and cramped places that hindered easy withdrawal. [4] Nor would they have succeeded in getting away without suffering for their rashness had not first a shout been heard from the rear and then an attack from that side too driven the king's troops mad with sudden panic. [5] Part broke in a rout; others, when they had made a stand, more because they had no place to flee than because they had sufficient will to fight, were cut off by the enemy pressing on from both front and rear. [6] The whole army could have been destroyed if the victors had pursued the routed enemy; [7] but the narrow roads and the rough country hindered the cavalry, the weight of their arms the infantry. [8] At first the king fled headlong and without looking back; then, having travelled five miles, suspecting what proved to be true, that the enemy could not follow on account of the unfavourable ground, he stopped on a certain hill and sent out messengers throughout the ridges and valleys to collect the stragglers in one place. [9] When all the army (except not more than two thousand men who were lost) had come to the same place, as if following some signal, they made for Thessaly in solid column. [10] The Romans followed as far as it was safe, killing and despoiling the slain, and plundered the king's camp, which, even when undefended, was difficult to approach; and spent that night in their own camp.