Plutarch, Caius Marius
Bernadotte Perrin, Ed.

20. After destroying many of the Ambrones the Romans withdrew and night came on; but in spite of so great a success the army did not indulge in paeans of victory, or drinking in the tents, or friendly converse over suppers, or that sweetest of all delights for men who have fought and won a battle, gentle sleep, but that night more than any other was spent in fears and commotions. [2] For their camp was still without palisade or wall, and there were still left many myriads of the Barbarians who had met with no defeat. These had been joined by all the Ambrones who survived the battle, and there was lamentation among them all night long, not like the wailings and groans of men, but howlings and bellowings with a strain of the wild beast in them, mingled with threats and cries of grief, went up from this vast multitude and echoed among the surrounding hills and over the river valley. [3] The whole plain was filled with an awful din, the Romans with fear, and even Marius himself with consternation as he awaited some disorderly and confused night-battle. However, the Barbarians made no attack either during that night or the following day, but spent the time in marshalling their forces and making preparations.

[4] Meanwhile, since the position of the Barbarians was commanded by sloping glens and ravines that were shaded by trees, Marius sent Claudius Marcellus thither with three thousand men-at-arms, under orders to lie concealed in ambush until the battle was on, and then to show themselves in the enemy's rear. The rest of his soldiers, who had taken supper in good season and then got a night's sleep, he led out at day-break and drew up in front of the camp, and sent out his cavalry into the plain. [5] The Teutones, seeing this, could not wait for the Romans to come down and fight with them on equal terms, but quickly and wrathfully armed themselves and charged up the hill. But Marius, sending his officers to all parts of the line, exhorted the soldiers to stand firmly in their lines, and when the enemy had got within reach to hurl their javelins, then take to their swords and crowd the Barbarians back with their shields; [6] for since the enemy were on precarious ground their blows would have no force and the locking of their shields no strength, but the unevenness of the ground would keep them turning and tossing about. This was the advice he gave his men, and they saw that he was first to act accordingly; for he was in better training than any of them, and in daring far surpassed them all.