C. Julius Caesar, Gallic War

Crassus, having received their arms and hostages, marched into the territories of the Vocates and the Tarusates. But then, the barbarians being alarmed, because they had heard that a town fortified by the nature of the place and by art, had been taken by us in a few days after our arrival there, began to send embassadors into all quarters, to combine, to give hostages one to another, to raise troops. Embassadors also are sent to those states of Hither Spain which are nearest to Aquitania , and auxiliaries and leaders are summoned from them; on whose arrival they proceed to carry on the war with great confidence, and with a great host of men. They who had been with Q. Sertorius the whole period [of his war in Spain] and were supposed to have very great skill in military matters, are chosen leaders. These, adopting the practice of the Roman people, begin to select [advantageous] places, to fortify their camp, to cut off our men from provisions, which, when Crassus observes, [and likewise] that his forces, on account of their small number could not safely be separated; that the enemy both made excursions and beset the passes, and [yet] left sufficient guard for their camp; that on that account, corn and provision could not very conveniently be brought up to him, and that the number of the enemy was daily increased, he thought that he ought not to delay in giving battle. This matter being brought to a council, when he discovered that all thought the same thing, he appointed the next day for the fight.