C. Julius Caesar, Gallic War

As this continued for several days, and their vigilance was relaxed by custom (an effect which is generally produced by time), the Bellovaci, having made themselves acquainted with the daily stations of our horse, lie in ambush with a select body of foot in a place covered with woods; to it they sent their horse the next day, who were first to decoy our men into the ambuscade, and then when they were surrounded, to attack them. It was the lot of the Remi to fall into this snare, to whom that day had been allotted to perform this duty; for, having suddenly got sight of the enemy's cavalry, and despising their weakness, in consequence of their superior numbers, they pursued them too eagerly, and were surrounded on every side by the foot. Being, by this means thrown into disorder they returned with more precipitation than is usual in cavalry actions, with the loss of Vertiscus the governor of their state, and the general of their horse, who, though scarcely able to sit on horseback through years, neither, in accordance with the custom of the Gauls, pleaded his age in excuse for not accepting the command, nor would he suffer them to fight without him. The spirits of the barbarians were puffed up, and inflated at the success of this battle, in killing the prince, and general of the Remi; and our men were taught by this loss, to examine the country, and post their guards with more caution, and to be more moderate in pursuing a retreating enemy.