John IV, Duke of Brittany

Parents

• Arthur II, Duke of Brittany
• Yolande of Dreux

Children

• John V, Duke of Brittany
• Joan of Brittany, Baroness of Drayton

Siblings

• Alice of Brittany
• Guy of Penthièvre
• John III, Duke of Brittany
• Beatrice of Brittany
• Marie de Montfort
• Blanche de Montfort
• Jeanne de Dreux-Bretagne, Dame de Nogent-le-Rotrou
• Pierre de Bretagne

Partners

• Joanna of Flanders