John II of Loon
John II of Loon, Lord of Jülich, Heinsberg and Löwenberg, son of Godfrey de Heinsberg, Count of Looz, and Philippa of Jülich, daughter of William V, Duke of Jülich, and Joanna of Hainaut. Although John was the first son of Godfrey, he did not inherit the countship of Looz, the title instead going to Arnold of Rumingy.
John married first Margaret and second Anna of Solms Countess of Solms-Braunfels. John and Margaret had four children:
- Johann III, married Walpurg von Mörs. Their daughter Margaret married Philip II of Nassau-Weilburg.
- Wilhelm I, married Elizabeth von Blankenheim, daughter of Gerhard IX, Count of Blankenheim, great-great-grandson of Gerard I, Count of Durbuy.
- John of Heinsberg, Bishop of Liège
- Philippa, married Wilhelm von Wied-Isenburg.
- Mary, married John IV, Count of Nassau-Siegen
- Jacoba, Abbess of Thorn.