Sweden. Courier mail. Beautiful and very rare letter by Royal courier, signed "Carolus" (Swedish King Karl IX), dated in Kalmar October 20, 1603. Nice ornament and with his royal paper seal attached on outside. Sent to the governor Torsten Lindormsson Forstena (1561–1631) at Elfsborg Castle (outskirts of Gothenburg). Torsten was then father to Field Marshal Lennart Torstensson. The King was in Kalmar to organize a new campaign in Polish Livonia (ongoing war with Poland), where he actually minted new coins. The Elfsborg (Älvsborg) fortress was conquered by the Danes May 22, 1612 (Kalmar War 1611–1613) and it was determined in the Peace that Sweden had to pay 1 million Riksdaler silver coins, to be paid in four instalments: 1616, 1617, 1618 and 1619 before Älvsborg was handed back. Very good quality although folded a long time ago.