The Kalmar War (1611–1613) was a war between Denmark–Norway and Sweden. Though Denmark-Norway soon gained the upper hand, it was unable to defeat Sweden entirely. The Kalmar War was the last time Denmark-Norway successfully defended its dominium maris baltici against Sweden, and it also marked the increasing influence of the two countries on Baltic politics. Background Since Denmark–Norway controlled the strait between the Baltic Sea and the North Sea, Sweden sought an alternative trade route through sparsely populated Lapland to avoid paying Denmark's Sound Dues. In 1607, Charles IX of Sweden declared himself "King of the Lapps in Nordland" and began "collecting" taxes in Norwegian territory, even south of Tromsø. Since the Sound Dues were Denmark's main source of income, Denmark-Norway did not want to see alternative trade routes established, particularly when established through Norwegian territory. Denmark-Norway protested. King Charles IX of Sweden ignored the protests of King Christian IV of Denmark and Norway. Finally, in April 1611, in response to Sweden's claim of a traditionally Norwegian area in Northern Norway, Denmark-Norway declared war upon Sweden and invaded. The war's beginnings The Danish-Norwegian side planned to attack Sweden on three fronts; from Kristianopel towards Kalmar, from Halmstad towards Jönköping, and from the Norwegian side towards the fortress of Älvsborg and thereafter further into Västergötland. A force of 6,000 Danish troops laid siege to the city of Kalmar, ultimately taking it. Norwegian forces, although stationed on the border, were instructed not to enter Sweden. On 26 June a Swedish force carried out the Storming of Kristianopel. In the summer of 1611, Swedish forces under Baltzar Bäck were ordered to invade Norwegian Jämtland. They did so, and armed Swedish peasants marched into Härjedalen. Both Jämtland and Härjedalen were conquered without much fight. However, Bäck's lack of ability, or will, to stop excesses against the population meant that the locals eventually rose up against the Swedish occupants. In the end, the Swedish troops could not handle the situation and were forced to leave Jämtland/Härjedalen in autumn 1612. 1612 On 20 October 1611 King Charles IX of Sweden died and was succeeded by his son, Gustavus Adolphus. On ascending the throne, Gustavus Adolphus sued for peace, but Christian IV saw an opportunity for larger victories, and strengthened his armies in southern Sweden. In response, Gustavus began conducting raids along the border between Denmark and Sweden. In a February raid, Gustavus nearly drowned at the