Undeterred by this resounding defeat, Charles of Navarre persisted in his grand design. In August 1364 his men began a fight back in Normandy while a small Navarrese army under Rodrigo de Uriz sailed from Bayonne to Cherbourg. Meanwhile Charles's brother Louis of Navarre led an army augmented by contingents pledged by the captains of the Great Company and the freebooter Seguin de Badefol through the Black Prince's territories and across France, evading the French royal forces sent to intercept him and arrived in Normandy on 23 September. Hearing of the collapse of the civil war in Brittany after the Battle of Auray (29 September), Louis abandoned his design to invade Burgundy and instead set about reconquering the Cotentin for Charles. Meanwhile Séguin de Badefol and his fellow-captains captured the town of Anse on the Burgundian border, but only to use it as a centre for raiding and plundering far and wide. They did Charles of Navarre's cause no discernible good, and Pope Urban V excommunicated Séguin. Although Charles offered Bernard-Aiz V, Lord of Albret, huge sums to take over the command of his forces around Burgundy, he finally realized he could not prevail against the King of France and must come to an accommodation with him. In May 1365, in Pamplona, he agreed to a treaty by which there was to be a general amnesty for his supporters, the remains of Navarrese executed and displayed for treason were to be returned to their families, prisoners would be mutually released without ransom. Charles was allowed to keep his conquests of 1364, except for the citadel of Meulan, which was to be razed to the ground. In compensation Charles received Montpellier in Bas-Languedoc. His claim to Burgundy was to be referred to the arbitration of the Pope. The Pope never in fact pronounced on the matter. It was an ignominious end to Charles's 15 years of struggle to create a major territory for himself and his line in France. Henceforth he resided mainly in his kingdom.
