Joanna of Flanders
Joanna, born in 1295, became the Duchess of Brittany after marrying John of Montfort in 1329. When her husband's claim to the throne was contested by Joan of Penthièvre, Joanna spent most of her life fighting for the rights of her husband and son to the dukedom of Brittany. The fight over the throne led to a civil war called La Guerre de Deux Jeanne, for both Joans were involved in the battles. The war lasted for 23 years.
When John of Montfort died in the middle of the war, Joanna announced that her son -- just a baby at the time -- was the rightful duke. She gathered an army, and dressed in armor herself, she led sieges. When she saw that the enemy had left their rear camp completely unguarded, "Jeanne la Flamme" (fiery Joan) took 300 men and burned their tents and supplies. The war lasted until 1364, when Joanna and the House of Montfort declared victory and Joanna's son was named the rightful Duke of Brittany.+
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