House of La Tour d'Auvergne
With the death of Charlotte de La Marck in 1594, the duchy and the title passed to her husband Henri de La Tour d'Auvergne and thereafter became the possession of the House of La Tour d'Auvergne. France again invaded Bouillon in 1676 during the Franco-Dutch War, but Godefroy Maurice de La Tour d'Auvergne retained the title. From this point on, although the Duchy of Bouillon was officially still a part of the Holy Roman Empire, it was in actuality a French protectorate. This state of affairs was confirmed by the 1678 Treaties of Nijmegen.