600. FREDERICK WILLIAM III (1770 - 1840) King of Prussia defeated by the French at Jena and Auerstedt, later regrouped his armies and defeated the French at Leipzig and Waterloo. Choice manuscript L.S. "Frederic Guillaume" as King, in French, 1p, folio, Berlin, Oct. 5, 1839, to the King of the Two Sicilies [Ferdinand II], acknowledging receipt of his letter containing the news that his Queen [Theresa] has given birth to a Prince [who would not survive]. Frederick sends his felicitations and prayers for the prosperity and good health of the newborn infant and the royal household. In fine condition. With original envelope, in a secretarial hand, bearing red-wax seal. $300 - 400