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.

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.

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.

It was a bloody combat because all wanted the battle to be decisive to put an end to the long and cruel war.

The left wing then folded in turn, the Count of Auxerre was captured, and the troops of Charles of Blois broke and fled.