At the beginning of 1364, after the failure of the negotiations of Évran, Montfort, with the assistance of John Chandos, came to attack Auray, which had been in the hands of Franco-Bretons since 1342. He entered the town of Auray and besieged the castle, which was blockaded by sea by the ships of Nicolas Bouchart coming from Le Croisic. Without food supplies, the besieged agreed to surrender the place, if help did not arrive before Michaelmas. Two days before, Charles of Blois had arrived east of the abbey of Lanvaux. Bertrand du Guesclin, who commanded the vanguard of the French troops, was in nearby Brandivy. On 28 September, du Guesclin landed on the left bank of the river, and took up position before the castle. To avoid being caught between the castle and the French Army, Montfort evacuated Auray and took up a position facing the enemy, on the slope of the right bank of the river. On the 29 September, attempts at agreement having failed, Charles of Blois prepared for the attack. His army crossed the river and lined up facing south, considered a bad position by some of his commanders because it was on a marshy plain north of the town and castle. Montfort followed the movement and lined up facing north, in a more dominating position. Rejecting the advice of du Guesclin, Charles of Blois then ordered the attack against Montfort's forces.
Involved forces
Franco-Breton army of Charles of Blois
On the left the Count of Auxerre, on the right Du Guesclin, in the center Charles of Blois. A weak reserve was not used. Each division had roughly 1,000 men.
On the right Olivier de Clisson, on the left the Englishman Sir Robert Knolles, in the centre Montfort and the Englishman Chandos. A significant reserve, under Sir Hugh Calveley, was also on hand ready to intervene.
The battle
The battle began with a short skirmish between the French arbalesters and the English archers. Then the men-at-arms engaged directly without seeking to maneuver. It was a bloody combat, because all wanted this battle to be decisive and put an end to the long and cruel war. Moreover, orders were given on both sides not to give quarter to captives. Each Anglo-Breton corps was attacked head on, one after the other, but the reserves restored the situation. Then the right wing of the Franco-Breton position was counterattacked and driven back and, not being supported by its own reserves, was folded up towards the center. The left wing then folded in turn, the Count of Auxerre was captured, and the troops of Charles of Blois broke and fled. Charles, having been struck down by a lance, was finished off by an English soldier, obeying orders to show no quarter. Du Guesclin, having broken all his weapons, was obliged to surrender to the English commander Chandos. Du Guesclin was taken into custody and ransomed by Charles V for 100,000 francs.
