1042. FREDERICK VI OF DENMARK (1768-1839) King of Denmark who aided in abolishing serfdom and slave trade; became ally of Napoleon I [1807]; lost Norway to Sweden in 1814. Manuscript letter of state "Fredericus" as King, 2pp., folio, Fredericksburg, Sept. 6, 1824, to "Ferdinand I...King of the Two Sicilies" only a few months before his death. Frederick has learned, "with an extraordinarily keen sense of joy", of the "auspicious birth of a Royal son, happily born to your son the Hereditary Prince Royal, Francis, Duke of Calabria and his wife...Maria Isabella [daughter of King Charles IV of Spain]...". The new-born son was Louis, Count of Aquila, who eventually married the daughter of the Emperor of Brazil. With original addressed envelope, bearing a fine huge impression of the Royal Seal. $250 - 350