Overview
Isabella of Brittany (; 1411 – c. 1444) was a daughter of John V, Duke of Brittany, and his wife, Joan of Valois. Isabella was a member of the House of Dreux.
Family
Isabella's maternal grandparents were Charles VI of France and Isabeau of Bavaria. Her paternal grandparents were John IV, Duke of Brittany and Joan of Navarre.
Isabella was related to three Queens of England. Two of her maternal aunts, Isabella of Valois and Catherine of Valois were queens of England and after the death of her paternal grandfather, John IV, her grandmother, Joan, became queen of England by her marriage to Henry IV of England. Isabella of Valois was married to Henry's predecessor, Richard II of England. Catherine of Valois was married to Henry IV's son, Henry V of England.
Marriage
On 1 October 1430, at Redon, Isabella married Guy XIV de Laval. Guy fought in many different battles in the Hundred Years' War and fought alongside Joan of Arc. Guy had been betrothed to Isabella's younger sister, Margaret, who died before the marriage could take place, so Guy married Isabella instead.
From Wikipedia (CC BY-SA 4.0).