Beatrice of Brittany French noble (1295–1384) Parents Yolande of Dreux Arthur II, Duke of Brittany Children Guy XI de Laval Catherine de Laval Guy XII de Laval Siblings John IV, Duke of Brittany Guy of Penthièvre Alice of Brittany John III, Duke of Brittany Marie de Montfort Jeanne de Dreux-Bretagne, Dame de Nogent-le-Rotrou Blanche de Montfort Pierre de Bretagne Partners Guy X de Laval