C. Julius Caesar, Gallic War

This part of Gaul having been tranquilized, he applies himself entirely both in mind and soul to the war with the Treviri and Ambiorix. He orders Cavarinus to march with him with the cavalry of the Senones , lest any commotion should arise either out of his hot temper, or out of the hatred of the state which he had incurred. After arranging these things, as he considered it certain that Ambiorix would not contend in battle, he watched his other plans attentively. The Menapii bordered on the territories of the Eburones, and were protected by one continued extent of morasses and woods; and they alone out of Gaul had never sent embassadors to Caesar on the subject of peace. Caesar knew that a tie of hospitality subsisted between them and Ambiorix: he also discovered that the latter had entered into an alliance with the Germans by means of the Treviri . Ho thought that these auxiliaries ought to be detached from him before he provoked him to war; lest he, despairing of safety, should either proceed to conceal himself in the territories of the Menapii, or should be driven to coalesce with the Germans beyond the Rhine . Having entered upon this resolution, he sends the baggage of the whole army to Labienus, in the territories of the Treviri and orders two legions to proceed to him: he himself proceeds against the Menapii with five lightly-equipped legions. They, having assembled no troops, as they relied on the defense of their position, retreat into the woods and morasses, and convey thither all their property.