War of the Breton Succession: Anglo-Bretons defeat the French in the Battle of Mauron.
The Battle of Mauron was fought in 1352 in Brittany during the Breton War of Succession between an Anglo-Breton force supporting the claim of Jean de Montfort and a Franco-Breton force supporting the claim of Charles de Blois. The Anglo-Bretons were victorious. The battle took place in the context of the Hundred Years War.
The War of the Breton Succession (French: guerre de Succession de Bretagne, Breton: Brezel hêrezh dugelezh Breizh) was a conflict between the Counts of Blois and the Montforts of Brittany for control of the Sovereign Duchy of Brittany, then a fief of the Kingdom of France. It was fought between 1341 and 12 April 1365. It is also known as the War of the Two Jeannes (French: guerre des deux Jeannes) due to the involvement of two queens of that name (Jeanne (Joanna) of Flanders and Jeanne de Penthièvre).The war formed an integral part of the early Hundred Years' War due to the proxy involvement of the French and English governments in the conflict; the French supported the Blois (female heir) whilst the English backed the Montforts (male heir). The rival kings supported the Sovereign Duke of the principle opposite to their own claims to the French throne—the Plantagenet having claimed it by female succession, and the Valois by male succession. Montfort was ultimately successful following the Battle of Auray in 1364.