C. Julius Caesar, Gallic War

Cassivellaunus, as we have stated above, all hope [rising out] of battle being laid aside, the greater part of his forces being dismissed, and about 4,000 charioteers only being left, used to observe our marches and retire a little from the road, and conceal himself in intricate and woody places, and in those neighborhoods in which he had discovered we were about to march, he used to drive the cattle and the inhabitants from the fields into the woods; and, when our cavalry, for the sake of plundering and ravaging the more freely, scattered themselves among the fields, he used to send out charioteers from the woods by all the well-known roads and paths, and to the great danger of our horse, engage with them; and this source of fear hindered them from straggling very extensively. The result was, that Caesar did not allow excursions to be made to a great distance from the main body of the legions, and ordered that damage should be done to the enemy in ravaging their lands, and kindling fires only so far as the legionary soldiers could, by their own exertion and marching, accomplish it.