The Congress turned it into an independent country under the name Duchy of Brunswick. Charles II (1815–1830) The underage Duke Charles, the eldest son of Duke Frederick William (who had been killed in action), was put under the guardianship of George IV, the Prince Regent of the United Kingdom and Hanover.
Charles's father and his advisors went about arranging a marriage for him. Their eyes fell upon Elisabeth Christine of Brunswick-Wolfenbüttel, the eldest child of Louis Rudolph, Duke of Brunswick-Wolfenbüttel. She was held to be strikingly beautiful by her contemporaries. On 1 August 1708, in Barcelona, Charles married her by proxy.
90. Duke Charles Louis Frederick of Mecklenburg (father of 45) 91. Princess Elizabeth Albertine of Saxe-Hildburghausen (mother of 45) 92. Frederick II, Landgrave of Hesse-Kassel (father of 46) 93. Princess Mary of Great Britain (mother of 46) 94. Charles William, Prince of Nassau-Usingen (father of 47) 95.