Rupert's family continued their attempts to regain the Palatinate during their time in The Hague. Money was short, with the family relying upon a relatively small pension from The Hague, the proceeds from family investments in Dutch raids on Spanish shipping, and revenue from pawned family jewellery. Frederick set about convincing an alliance of nations—including England, France and Sweden—to support his attempts to regain the Palatinate and Bohemia. By the early 1630s Frederick had built a close relationship with the Swedish King Gustavus, the dominant Protestant leader in Germany. In 1632, however, the two men disagreed over Gustavus' insistence that Frederick provide equal rights to his Lutheran and Calvinist subjects after regaining his lands; Frederick refused and set off to return to The Hague. He died of a fever along the way and was buried in an unmarked grave. Rupert had lost his father at the age of 13, and Gustavus' death at the battle of Lützen in the same month deprived the family of a critical Protestant ally. With Frederick gone, King Charles proposed that the family move to England; Rupert's mother declined, but asked that Charles extend his protection to her remaining children instead.