C. Julius Caesar, Gallic War

When the towers had now approached the walls, Caesar ascertained from the captives that Vercingetorix after destroying the forage, had pitched his camp nearer Avaricum , and that he himself with the cavalry and light-armed infantry, who generally fought among the horse, had gone to lay an ambuscade in that quarter, to which he thought that our troops would come the next day to forage. On learning these facts, he set out from the camp secretly at midnight, and reached the camp of the enemy early in the morning. They having quickly learned the arrival of Caesar by scouts, hid their cars and baggage in the thickest parts of the woods, and drew up all their forces in a lofty and open space: which circumstance being announced, Caesar immediately ordered the baggage to be piled, and the arms to be got ready.