Gallic War

After spending several days in the same camp, the guards of the Bellovaci, learning that Caius Trebonius was advancing nearer with his legions, and fearing a siege like that of Alesia , send off by night all who were disabled by age or infirmity, or unarmed, and along with them their whole baggage. While they are preparing their disorderly and confused troop for march (for the Gauls are always attended by a vast multitude of wagons, even when they have very light baggage), being overtaken by day-light, they drew their forces out before their camp, to prevent the Romans attempting a pursuit before the line of their baggage had advanced to a considerable distance. But Caesar did not think it prudent to attack them when standing on their defense, with such a steep hill in their favor, nor keep his legions at such a distance that they could quit their post without danger: but, perceiving that his camp was divided from the enemy's by a deep morass, so difficult to cross that he could not pursue with expedition, and that the hill beyond the morass, which extended almost to the enemy's camp, was separated from it only by a small valley, he laid a bridge over the morass and led his army across, and soon reached the plain on the top of the hill, which was fortified on either side by a steep ascent. Having there drawn up his army in order of battle, he marched to the furthest hill, from which he could, with his engines, shower darts upon the thickest of the enemy.

The Gauls, confiding in the natural strength of their position, though they would not decline an engagement if the Romans attempted to ascend the hill, yet dared not divide their forces into small parties, lest they should be thrown into disorder by being dispersed, and therefore remained in order of battle. Caesar, perceiving that they persisted in their resolution, kept twenty cohorts in battle array, and, measuring out ground there for a camp, ordered it to be fortified. Having completed his works, he drew up his legions before the rampart and stationed the cavalry in certain positions, with their horses bridled. When the Bellovaci saw the Romans prepared to pursue them, and that they could not wait the whole night, or continue longer in the same place without provisions, they formed the following plan to secure a retreat. They handed to one another the bundles of straw and sticks on which they sat (for it is the custom of the Gauls to sit when drawn up in order of battle, as has been asserted in former commentaries), of which they had great plenty in their camp, and piled them in the front of their line; and at the close of the day, on a certain signal, set them all on fire at one and the same time. The continued blaze soon screened all their forces from the sight of the Romans, which no sooner happened than the barbarians fled with the greatest precipitation.

Though Caesar could not perceive the retreat of the enemy for the intervention of the fire, yet, suspecting that they had adopted that method to favor their escape, he made his legions advance, and sent a party of horse to pursue them; but, apprehensive of an ambuscade, and that the enemy might remain in the same place and endeavor to draw our men into a disadvantageous situation, he advances himself but slowly. The horse, being afraid to venture into the smoke and dense line of flame, and those who were bold enough to attempt it being scarcely able to see their horse's heads, gave the enemy free liberty to retreat, through fear of an ambuscade. Thus by a flight, full at once of cowardice and address, they advanced without any loss about ten miles, and encamped in a very strong position. From which, laying numerous ambuscades, both of horse and foot, they did considerable damage to the Roman foragers.

After this had happened several times, Caesar discovered from a certain prisoner, that Correus, the general of the Bellovaci, had selected six thousand of his bravest foot and a thousand horse, with which he designed to lie in ambush in a place to which he suspected the Romans would send to look for forage, on account of the abundance of corn and grass. Upon receiving information of their design Caesar drew out more legions than he usually did, and sent forward his cavalry as usual, to protect the foragers. With these he intermixed a guard of light infantry, and himself advanced with the legions as fast as he could.