Sweden. 1850, military prephilately. The Danish-German War (1848–1851). A beautiful paid letter to the Swedish field doctor Bergholtz within the Swedish-Norwegian army, Flensburg from Christianstad 27.6.1850 with notations "Franco Gränsen" and listing nr 2. Conveyed by the Royal Danish Mail, probably in closed mail bags to the Swedish-Norwegian forces in Schleswig-Holstein considering the lack of Danish postal notations and cancels. Excellent quality and a truly postal history exhibition item!