The Scanian War is generally taken to mark the beginning of the decline of Sweden as a Great Power. During the Thirty Years War and the Northern War of 1655-60 (First or Second Northern War in different historical traditions), Sweden had established a Baltic Empire, expelling Denmark from her remaining possessions in the south of modern Sweden (amongst them Scania), and taking control of Pomerania, Wismar and Bremen in northern Germany. This had come at a serious financial cost, and after the peace of 1660 Sweden was looking for a lucrative alliance – during the Thirty Years War much of the cost of the Swedish army had been paid by her allies.
1660 also saw the beginning of a period of minority rule, with the accession of Charles XI. For twelve years power was shared between the regent, Chancellor Magnus Gabriel de la Gardie and a small number of the higher ranked aristocrats. In 1668 de la Gardie’s opponents arranged for Sweden’s entry into the Triple Alliance, aimed at the French. This move promised a subsidy without a serious commitment to expensive military action, but three days before the subsidy treaty was signed the War of Devolution ended and two years later the Triple Alliance ended when Charles II of England allied with Louis XIV of France.
The end of the Triple Alliance left Sweden looking for a new alliance. Her nearest enemy, Denmark, had entered alliances with England in 1661, France in 1663 and the United Provinces in 1666. Things were further complicated in March 1672 by the outbreak of the Dutch War (1672-1678), which started as a struggle between France and the Dutch, but would soon expand. In April 1672 de la Gardie negotiated a treaty with the French. Sweden would receive 400,000 riksdalers per year as long as they maintained an army 16,000 strong in their German possessions. That would be increased to 600,000 riksdalers if Sweden entered the war.
The Dutch War began to expand in 1674. The Empire, Denmark and Brandenburg entered the war against France. In their turn the French put pressure on Sweden to enter the war. They had already increased their subsidy to 900,000 riksdalers in return for an increase in the size of the Swedish army to 22,000 men.
Late in 1674 that pressure finally became too much to resist. The French threatened to withdraw their subsidy, while food was running short in Pomerania. An army 13,000 strong under Karl Gustav Wrangel invaded Brandenburg. Frederick William of Brandenburg and Prussia retreated in front of the Swedish advance, denying them supplies, until finally on 18/28 June 1675 he defeated the Swedes at Fehrbellin.
Encouraged by this victory, Sweden’s enemies entered the war. Sweden now found herself faced with a war against Brandenburg, the Emperor Leopold I, the Dutch, the Danes and the Bishop of Münster. Unsurprising Swedish morale began to crumble under the strain. Christian V of Denmark took an army 16,000 strong south into Germany, capturing Wismar and Bremen. Over the next three years Sweden lost all of her German possessions.
Sweden also lost control of the sea. The Danes won naval victories at Jasmund (25 May 1675) under Niels Juel, defeated Gustaf Otto Stenbock in October 1675, and on 30 June 1677 Niels Juel defeated Evert Horn at Köge Bay or Kjöge Bight. The Swedes also suffered a defeat against the Dutch under Cornelis Tromp at Öland.
With control of sea the Danes were able to launch an invasion of mainland Sweden. On 29 June 1676 (Old Style) a 14,000 strong Danish army landed at Rå in Scania. By August the Danes had captured Helsingborg, Landskröna and Kristianstad. The Swedish position looked desperate, but Charles XI was soon to prove his ability. A Danish army was defeated at Halmstadt (August 1676), before on 4/14 December 1676 Charles XI inflicted a bloody defeat on the Danes (Battle of Lund).
Lund established Charles as a significant military leader, but it did not end the fighting in southern Sweden. The Danes lost control of Helsingborg, and were unable to retake it during 1677. They failed to take Malmo and were defeated at Landskröna in July 1677. In 1678 they managed to hold on to Helsingborg, but lost Kristianstad. Although Sweden had lost her German empire, she had retained her military reputation.
The Dutch War came to an end in 1678. France may have been disappointed in her ally, having paid heavily for military aid that had not amounted to much, eventually finding herself in a position where it was Sweden that needed aid, but Louise XIV did not forget his ally during the peace negotiations. In the Peace of St. Germain (June 1679) Brandenburg returned most of Pomerania. The Peace of Fontainebleu (August 1679) saw the status quo restored in Holstein-Gottorp. In the Peace of Lund (September 1679) Denmark recognised Sweden’s possessions of the areas she had lost in 1660. Finally, Wismar and Bremen were returned to Sweden. Despite the return of these provinces, Sweden ended the war in the same terrible financial state that she had entered it.