Joan_of_Valois,_Countess_of_Hainaut--Philip_III_of_France

Joan of Valois (c. 1294 – 1342) was a Countess consort of Hainaut, Holland, and Zeeland, by marriage to William I, Count of Hainaut. She acted as regent of Hainaut and Holland several times during the absence of her spouse, and she also acted as a political mediator.
She was the second eldest daughter of the French prince Charles, Count of Valois, and Margaret, Countess of Anjou and Maine. As the sister of King Philip VI of France and the mother-in-law of King Edward III of England, she was ideally placed to act as mediator between them.