Autograph Letter Signed ‘Mary Adelaide’, to “My dear Duchess” (of Northumberland), requesting a favour, “the Prince of Orange is very anxious to obtain an invitation to your ball on the 12th. … The Prince is staying at the Palace Hotel”, hoping the Duke’s health has improved, etc. 3 pp. 7 x 4 inches, in good condition, traces of former mounting along one edge, crowned raised monogram in red at head. 10 June 1863. Princess Mary Adelaide (1833-97), Duchess of Teck, mother of Queen Mary, consort of George V. Mary Adelaide was the youngest of the three children of the seventh son of George III, Adolphus Frederick, Duke of Cambridge (1774–1850), and his wife, Princess Augusta (1797–1889).