C. Julius Caesar, Gallic War

Caesar, when he perceived that the seventh legion, which stood close by him, was also hard pressed by the enemy, directed the tribunes of the soldiers to effect a junction of the legions gradually, and make their charge upon the enemy with a double front; which having been done, since they brought assistance the one to the other, nor feared lest their rear should be surrounded by the enemy, they began to stand their ground more boldly, and to fight more courageously. In the mean time, the soldiers of the two legions which had been in the rear of the army, as a guard for the baggage-train, upon the battle being reported to them, quickened their pace, and were seen by the enemy on the top of the hill; and Titus Labienus, having gained possession of the camp of the enemy, and observed from the higher ground what was going on in our camp, sent the tenth legion as a relief to our men, who, when they had learned from the flight of the horse and the sutlers in what position the affair was, and in how great danger the camp and the legion and the commander were involved, left undone nothing [which tended] to dispatch.