The battle of Crecy established that the English had developed a "new" tactic of war, to counter the French army's overwhelming armoured cavalry. Learning from the Scots and the Welsh who had defeated English armoured troops by using rough terrian, and light troops armed with missiles, to pick the English off before they could reach close quarters, Edward III, at Crecy, placed archers along the front of his army who, as the french advanced, withdrew to the flanks, firing as they went. The army of Philip IV of France was cut apart, and the chivalry of France decimated (though many critics now say that their indiscipline and hot-headedness added to their destruction.
The French sought to counter this tactic in their turn, and their marshal, Guy de Nesle, evolved a scheme of dismounting his chivalry (so that their horses (themselves an expensive peice of equipment) could not be shot from under them) thereby making them less vulnerable. In 1351, at Mauron, he met Sir Walter Bentley. De Nesle kept one 'battle' of men mounted, and used them to disrupt and drive off one flank of archers, and on the other flank and in the centre, used the disarmed men to force Bentley's troops back. The tactic floundered, however, because the french cavalry, having cleared the flank, failed to engage with the English centre, and because Bentley had formed his troops up at the top of a hill, and by the time de Nesle's men had forced the English back, they were very vulnerable to a gravity-assisted counter-attack. Once in retreat the French were cut apart, and de Nesle was killed, along with many knights.
- One other effect of Mauron was that the French Order of the Star (set up by King John the Good to emulate and outshine the English Order of the Garter was severely reduced from its initial contingent of 500 knights, because of their oath never to retreat further than a short distance from a battle. The rest of the Order were to suffer a like fate at Poitiers.
- Mauron also pointed the weakness of the flank-archer tactic: they needed cover to protect them from a cavalry charge. The French attacked on the more open flank, and the English had not troubled to protect their archers with either pit-traps or earthern or wooden emplacements. Both sides learned: the problem (for the French) was that, hereafter, the English would remember to put their weaker troops near woods or other obstacles, thus countering or negating the cavalry's mobility and speed.