A diplomatist and man of letters, born at Korbach; in Waldeck; studied at Marburg and Göttingen; became acquainted with Niebuhr at Berlin; studied Oriental languages under Silvestre de Sacy at Paris; became secretary, under Niebuhr, to the Prussian embassy at Rome; recommended himself to the king, and succeeded Niebuhr; became ambassador in Switzerland and then in England; was partial to English institutions, and much esteemed in England; wrote the "Church of the Future," "Hippolytus and his Age," &c. (1791-1860).