Montfort of Brittany - Rise To Power

Rise To Power

Count John of Montfort (1295–1345) was the sole surviving son of Yolande of Dreux, Countess of Montfort suo jure (and dowager queen of Scotland) from her second marriage to Arthur II, Duke of Brittany. John inherited in 1322 Montfort-l'Amaury from his mother. However, he was only a younger son of the Duke, who had several older sons from his first marriage. John only received some appanage in Brittany, and his maternal inheritance, a countship, was a much more important possession.

However, his eldest half-brother, John III, Duke of Brittany, was childless in spite of his three marriages. Duke John III died in 1341, and his duchy's nobles proclaimed Countess Joan of Dreux reigning duchess. She was the daughter of the late Guy de Bretagne, comte de Penthièvre, Duke John III's younger full brother, and thus John III's full niece.

John of Montfort however invoked both the principle of Salic Law (allowing only males to succeed) and the principle of proximity of blood (as used earlier e.g. by John I of England against Arthur of Brittany), having himself proclaimed Duke John IV. This led to the Breton War of Succession, a part of the Hundred Years' War. His patron in this quest was king Edward III of England. The rivals, Duchess Joanna and her husband Charles of Blois were supported by the Valois kings of France. John IV died without accomplishing his objective of becoming sole ruler of Brittany, but his wife Joanna of Flanders continued the fight in the name of their son John V, Duke of Brittany (1339/40-99) who ultimately got the upper hand in the strife.

In the midst of the conflict, in 1352, the Estates of Brittany (États de Bretagne) were established. They would develop into the Duchy's parlement.