1356 The Battle of Poitiers
The Hundred Years War was one of the nastiest and most unnecessary conflicts in European history, waged on the flimsiest of pretexts and conducted, by the English at least, as a money-spinning proposition. It pitted a small and not-terribly-prosperous country against the richest and largest nation on the continent but England did surprisingly well for so long because of French disunity and, at critical moments, the superiority of dismounted bowman against heavy feudal cavalry.
One such moment occurred on this date in 1356 when an English army, led by Edward, “the Black Prince, heir to the throne, blundered into a much larger French force when returning from a raid. The result was the Battle of Poitiers and disaster for France.
The disparity in the size of the armies made Prince Edward look for a negotiated way out. The English offered to restore all the towns and castles which they had taken in the course of this campaign, to give up, unransomed, all their prisoners, and to bind themselves by oath to refrain for seven years from bearing arms against the king of France. But King Jean II, confident of victory, insisted on the Black Prince and a hundred of his best knights surrendering themselves as prisoners, a proposition which Edward and his army indignantly rejected.
When battle was joined the English longbow men repulsed charges by French knights, sending them into disarray and causing a large body of other cavalry to retreat without having seen action. Edward then charged with his own armoured horsemen and achieved victory by capturing Jean and one of his sons.
Jean was taken back to comfortable captivity in the Tower of London while an extortionate ransom was being negotiated. In the meantime France fell into chaos, peasant rebellions, and noble disunity from it took decades to recover.