C. Julius Caesar, Gallic War

Caesar, when he observes this, draws off his forces to the next hill, and sent the cavalry to sustain the attack of the enemy. He himself, meanwhile, drew up on the middle of the hill a triple line of his four veteran legions in such a manner, that he placed above him on the very summit the two legions, which he had lately levied in Hither Gaul, and all the auxiliaries; and he ordered that the whole mountain should be covered with men, and that meanwhile the baggage should be brought together into one place, and the position be protected by those who were posted in the upper line. The Helvetii having followed with all their wagons, collected their baggage into one place: they themselves, after having repulsed our cavalry and formed a phalanx, advanced up to our front line in very close order.