Joanna of Flanders

Joanna of Flanders was Duchess of Brittany through her marriage to John of Montfort and was involved in the defense of her husband’s and later her son’s claim to the dukedom during the War of the Breton Succession. After her husband was captured, she led the Montfortist cause, demonstrating skill as a military leader. She was eventually confined to Tickhill Castle by order of King Edward III of England.

Joanna was the daughter of Louis I, Count of Nevers, and Joan, Countess of Rethel. She married John of Montfort in 1329, who claimed the title of Duke of Brittany. Their claim was contested by the House of Blois. Following her husband’s imprisonment by the French, Joanna took charge, raising an army, and successfully defending their territories. Her military actions earned her praise from chroniclers such as Jean Froissart and historians like David Hume.