Joan of Flanders

Joan of Flanders, called Jeanne la Flamme (c. 1295–1374), was the daughter of Louis I, Count of Nevers, and in 1329 married John of Montfort, claimant to Brittany. The childless death of Duke John III in 1341 sparked a succession dispute, with England supporting the Montfort claim and France backing Charles of Blois.

When Philip VI imprisoned her husband, Joan took command of the Montfort cause herself. At the 1342 siege of Hennebont she fought in armour, led three hundred men out to burn Charles of Blois's camp and held the town until English relief arrived.

She later took refuge in England, where Edward III confined her at Tickhill Castle, for reasons historians dispute. She died in September 1374; her son John IV later became Duke of Brittany.