Second Treaty of Guerande Between Yann IV of Brittany & Charles VI of France Recognizes Breton Independence

The second Treaty of Guérande (1381) established Brittany’s neutrality in the Anglo-French conflict, and was accorded between Duke John V of Brittany and King Charles VI of France.

This treaty marked a significant event in the history of the Brittany succession wars, a complex and prolonged conflict involving various factions vying for control of the Duchy of Brittany. The War of the Breton Succession was part of a larger series of conflicts linked to the Hundred Years’ War between France and England. The war in Brittany began following the death of Duke John III in 1341, which left no clear heir to the duchy. The main contenders for the ducal crown were Jeanne de Penthièvre, niece of the late duke, and her husband Charles of Blois, who were supported by the King of France, and John of Montfort, a younger half-brother of the late duke, supported by the King of England.

First Treaty of Guérande

The first treaty of Guérande, signed on 12 April 1365, ended the Breton War of Succession.

In this war, two heirs of John III, Duke of Brittany disputed each other’s claim to be Duke of Brittany. Joanna de Penthievre and her husband Charles de Blois were supported by the King Charles V of France in the contest against John of Montfort, his son John IV and their English allies. Montfort died during the war after a period of imprisonment. Charles de Blois died in the Battle of Auray in 1364, which decided the war.