Joanna of Hainaut Dutch noblewoman (1315–1374) Parents Joan of Valois, Countess of Hainaut William I, Count of Hainaut Children Philippa von Jülich Isabella von Jülich William II, Duke of Jülich Johanna von Jülich Richardis of Jülich Gerhard VI of Jülich Siblings Philippa of Hainault William II of Hainaut Margaret II, Countess of Hainaut Catherine d'Avesnes Isabella d'Avesnes Jan Aelman Partners William V, Duke of Jülich