The Peace of Copenhagen of 6 June 1660 ended the Swedish-Danish War of 1658-60. Combined with the Peace of Oliva of 3 May 1660 it ended the Northern War of 1655-60. It also replaced the Peace of Roskilde of 1658 that had ended the previous Swedish-Danish War of 1657-58.
The Peace of Roskilde had seen Denmark surrender its remaining provinces on the southern tip of the Scandinavian Peninsula (Scania, Bohuslän and Blekinge) as well as the island of Bornholm and Trondheim on the Norwegian coast. Danish control over the entrance to the Baltic had been broken, with the shore opposite Copenhagen in Swedish hands.
The war of 1658-60 saw the Danes gain support from Holland, Austria, Brandenburg and Poland-Lithuanian. The death of Charles X of Sweden had ended Swedish enthusiasm for the war. Despite these Swedish setbacks, the terms of the Peace of Copenhagen were still rather generous. Of the provinces lost in 1658 only Bornholm and Trondheim were returned to Denmark. Scania, Bohuslän and Blekinge were retained by the Swedes, giving them a much stronger position in the southern Baltic. The Swedish naval base of Karlskrona would built on the southern shore of Blekinge.