Battle of Vittsjö after being surprised by a Danish army. In early 1612, Denmark-Norway attacked and eventually conquered two fortresses on the border between the fighting countries, Älvsborg and Gullberg, both in present-day Gothenburg. This was a major setback for Sweden, as the country now lacked access to the sea in the west. Having achieved this success, and aiming to end the war as soon as possible, the Danish command ordered an attack deep into Sweden, towards the capital of Stockholm. However, this proved to be a failure. Scorched earth methods and guerrilla warfare from the Swedish side made this a very difficult task and many of the mercenaries in the Danish army deserted since they did not receive their pay. Thus, the Danish army could never mount a serious attack on the capital itself. Peace of Knäred England and the Dutch Republic were also invested in the Baltic Sea trade, and pressured to curtail Denmark-Norway's power by ending the Kalmar War before a decisive victory could be attained. The Danes and Norwegians, while well-equipped and strong, had relied heavily on mercenary forces and Christian IV, low on funds, was finally amenable to persuasion in 1613. With the intercession of James I of England, the Treaty of Knäred was signed on 20 January 1613. Denmark–Norway reached its victory, restoring Norwegian control of Sweden's land route through Lapland by incorporating Lapland as a part of Norway. Further, Sweden had to pay a high ransom for two fortresses (Älvsborg and Gullberg), two towns and six surrounding hundreds captured by Denmark-Norway. Sweden, however, achieved a major concession — the right of free trade through the Sound Strait, becoming exempt from the Sound toll. Aftermath One of the results coming out of the Kalmar War was the establishment of Denmark–Norway as a competent army recognized throughout Europe. The rise of the Maritime Powers including Great Britain and the Dutch established a rivalry for power in the Baltic Sea. Archduke Albert of the Habsburgs sought out aid from the Hanseatics in order to challenge the military prowess of King Christian IV. Because the Dano-Norwegian Alliance did not achieve a total overall victory, Sweden would recover under Gustavus Adolphus. Surprisingly enough, Sweden and the Danish and Norwegians would enter into a brief alliance in the coming Thirty Years' War. The Kalmar War as well as the Northern Seven Years' War marked the beginning of centuries of