Joanna of Hainault (1315–1374) was a Duchess of Jülich by marriage to William V, Duke of Jülich. She was the third daughter of William I, Count of Hainaut, and Joan of Valois. She was a younger sister of Philippa of Hainault, Queen of England, and Margaret II, Countess of Hainault. Life Joanna married William V, Duke of Jülich, their children were as follows: Gerhard VI of Jülich, Count of Berg and Ravensberg, grandfather of Adolph I, Duke of Cleves William II, Duke of Jülich Richardis of Jülich, married Count Engelbert III of the Mark Philippa of Jülich, married Godfrey II of Heinsberg Reinold Joanna of Jülich, married William I, Count of Isenburg-Wied Isabella of Jülich, married John Plantagenet, 3rd Earl of Kent Ancestry 1315 births 1374 deaths Avesnes family 14th-century French people 14th-century French women