C. Julius Caesar, Gallic War

Since Indutiomarus was daily advancing up to the camp with greater defiance, all the cavalry of the neighboring states which he [Labienus] had taken care to have sent for, having been admitted in one night, he confined all his men within the camp by guards with such great strictness, that that fact could by no means be reported or carried to the Treviri . In the mean while, Indutiomarus, according to his daily practice, advances up to the camp and spends a great part of the day there: his horse cast their weapons, and with very insulting language call out our men to battle. No reply being given by our men, the enemy, when they thought proper, depart toward evening in a disorderly and scattered manner, Labienus unexpectedly sends out all the cavalry by two gates; he gives this command and prohibition, that, when the enemy should be terrified and put to flight (which he foresaw would happen, as it did), they should all make for Indutiomarus, and no one wound any man before he should have seen him slain, because he was unwilling that he should escape, in consequence of gaining time by the delay [occasioned by the pursuit] of the rest. He offers great rewards for those who should kill him: he sends up the cohorts as a relief to the horse. The issue justifies the policy of the man, and since all aimed at one, Indutiomarus is slain, having been overtaken at the very ford of the river, and his head is carried to the camp, the horse, when returning, pursue and slay all whom they can. This affair having been known, all the forces of the Eburones and the Nervii which had assembled, depart; and for a short time after this action, Caesar was less harassed in the government of Gaul.