Charles, Prince of Nassau-Usingen  Charles, Prince of Nassau-Usingen (31 December 1712 – 21 June 1775), was from 1718 to 1775 Prince of Nassau-Usingen. Charles was born in Usingen, the son of William Henry of Nassau-Usingen and Countess Charlotte Amalia of Nassau-Dillenburg. His father died in 1718, when he was still a minor. His mother acted as regent for Charles and his younger brother William Henry II. In 1728, he inherited the counties of Nassau-Ottweiler, Nassau-Idstein and Nassau-Saarbrücken from his second cousin Frederick Louis. These counties were then added to his county of Nassau-Usingen. In 1734, he was declared an adult by Emperor Charles VI. In 1735, he and William Henry II divided their inheritance. Charles received Usingen, Idstein, Wiesbaden and Lahr; William Henry II received Nassau-Saarbrücken and some smaller territories. He then moved his residence from Usingen in the Taunus to Schloss Biebrich in Biebrich and continued the progressive policies of his mother. Charles died in 1775 in Biebrich and was succeeded by his son Charles William. On 26 December 1734 Charles married Duchess Christine Wilhelmine of Saxe-Eisenach (born: 1711), a daughter of Duke John William III. The marriage produced four children:   In the second, morganatic marriage, Charles married Magdalene Gross from Wiesbaden (born: 1712). From this marriage he also had four children: