THE SCENE: In a conflict against the Belgae, Julius Caesar benefited from a mistake that was surely one of the biggest unforced errors in military history.
THE TEXT: The Belgae now realized that their hope of crossing the river was vain, and that the Romans would not advance into an unfavourable position to fight. Their own supply of grain, too, was running short. Summoning a council of war, therefore, they decided that the best course was for every man to return to his own home and wait to see whose territory the Romans invaded first; they would then rally from all parts to its defense, and would have the advantage of fighting in friendly country, where their home supplies of grain would be available.
In pursuance of their resolve the Belgae left camp some time before midnight amid great uproar and confusion, without any proper order or discipline, since every man wanted to reach home quickly and tried to get the first place on the road. The result was that their departure resembled a rout. The movement was immediately reported to Caesar by his scouts, but he was afraid at first that an ambush was being laid, because the reason for their retreat was not yet apparent, and therefore kept all his forces in camp. At daybreak, however, the reports of his patrols satisfied him that the enemy really were retreating, whereupon he sent forward the cavalry to delay the march of their rearguard.
These troops attacked their column from behind and pursued it for many miles, killing a large number as they fled, for while the rearguard, with which our men were actually in contact, halted and put up a gallant resistance, all those in front, imagining that they were far enough off to be safe, and not being under the immediate necessity of defending themselves or under the control of anyone in authority, broke their ranks directly they hear the shouting of the combatants and tried to escape. Thus our troops were able, without any risk, to kill as many of them as there was time to kill.
– The Conquest of Gaul, Julius Caesar, 1st Century BC
