Topic summary
Northern War of 1655–1660
Brandenburg-Prussia (1656–57)
Transylvania
Swedish Lithuania
Cossack HetmanateDenmark–Norway (from 1657)
Habsburg MonarchyRussia (1656–58)
Brandenburg-Prussia (1655–56, 1657–60)
Crimean Khanate
Dutch RepublicArvid Wittenberg#
Magnus de la Gardie
Carl Gustaf Wrangel
Janusz Radziwiłł#B. RadzwiłłFrederick William I
George II
Bohdan KhmelnytskyStefan Czarniecki
Paweł Jan Sapieha
Wincenty Gosiewski
Frederick III
Alexis of Russia
Frederick William I
Jean-Louis de Souches
The Northern War of 1655–1660 was fought between the Swedish Empire and the Polish–Lithuanian Commonwealth, with participation at different times by Russia, Brandenburg-Prussia, the Habsburg monarchy, and Denmark–Norway. It ended with the treaties of Copenhagen and Oliva in 1660.
In 1655, Charles X took advantage of the Russo-Polish War (1654–67) to over-run western Poland. The Grand Duchy of Lithuania was annexed by Sweden, and John II Casimir Vasa took refuge in Vienna. He managed to regain parts of his kingdom in 1656, and the conflict widened when Russia declared war on Sweden, supported by Emperor Leopold and Frederick III of Denmark.
Previously allied with Sweden, Brandenburg switched sides in 1657 when Casimir granted Frederick William I sovereignty over the Duchy of Prussia. That winter, Charles X invaded Denmark and forced Frederick to withdraw from Southern Sweden. However, a second Swedish offensive failed, and by 1659 the war had become one of attrition, with neither side able to gain a decisive advantage.
After Charles died in February 1660, his son made peace with his opponents. Sweden kept most of its gains from Denmark, but the belligerents largely returned to the status quo ante bellum.