Treaty of Copenhagen (1660) in the context of "Second Northern War"

Skåneland is a region on the southern Scandinavian Peninsula. It includes the Swedish provinces of Blekinge, Halland, and Scania. The Danish island of Bornholm is traditionally also included. Skåneland has no official recognition or function and the term is not in common usage. Equivalent terms in English and Latin are "the Scanian Provinces" and "Terrae Scaniae" respectively. The term is mostly used in historical contexts and not in daily speech. In Danish, Skånelandene is used more often. The terms have no political implications as the region is not a political entity but a cultural region, without officially established administrative borders.

The provinces making up Skåneland were part of Denmark from at least the 9th century, sometimes referred to as the "Eastern Province", after the 12th-century civil war called the Scanian Uprising. Blekinge was a part of Sweden until the early 13th century when it became part of Denmark (the Danish Census Book contains the first secure written evidence of Danish control). The provinces were part of the territory ceded to Sweden in 1658 under the Treaty of Roskilde, but after an uprising on Bornholm, that island was returned to Denmark in 1660, under the Treaty of Copenhagen. Since then, the Dano–Swedish border has remained unchanged in times of peace.

The Treaty of Roskilde was negotiated at Høje Taastrup Church and was concluded on 26 February (OS) or 8 March 1658 (NS) during the Second Northern War between Frederick III of Denmark–Norway and Karl X Gustav of Sweden in the Danish city of Roskilde. After a devastating defeat, Denmark–Norway was forced to give up a third of its territory to save the rest, the ceded lands comprising Blekinge, Bornholm, Bohuslän, Scania and Trøndelag, as well as Halland.

After the treaty entered into force, Swedish forces continued to campaign in the remainder of Denmark–Norway, but had to withdraw from the Danish isles and Trøndelag in the face of a Dano–Norwegian and Dutch alliance. The Treaty of Copenhagen restored Bornholm to Denmark and Trøndelag to Norway in 1660, while the other provinces transferred in Roskilde remained Swedish.

The Treaty or Peace of Oliva (Polish: Pokój Oliwski; Swedish: Freden i Oliva; German: Vertrag von Oliva) was one of the peace treaties ending the Second Northern War (1655–1660). It was signed on 3 May [O.S. 23 April] 1660. The Treaty of Oliva, the Treaty of Copenhagen in the same year, and the Treaty of Cardis in the following year marked the high point of the Swedish Empire.

At Oliwa (Oliva), Poland, peace was made between Sweden, the Polish–Lithuanian Commonwealth, the Habsburgs and Brandenburg-Prussia. Sweden was accepted as sovereign in Swedish Livonia, Brandenburg was accepted as sovereign in Ducal Prussia and John II Casimir Vasa withdrew his claims to the Swedish throne but was to retain the title of a hereditary Swedish king for life. All occupied territories were restored to their prewar sovereigns. Catholics in Livonia and Prussia were granted religious freedom.

Bornholm (Danish pronunciation: [pɒːnˈhʌlˀm]) is a Danish island in the Baltic Sea, to the east of the rest of Denmark, south of Sweden, northeast of Germany and north of Poland.

Strategically located, Bornholm has been fought over for centuries. It has usually been ruled by Denmark, but also by Sweden and by Lübeck. The ruin of Hammershus, at the northwestern tip of the island, is the largest medieval fortress in northern Europe, testament to the importance of its location. Bornholm and Ertholmene comprise the last remaining Danish territory in Skåneland east of Øresund, having been surrendered to Sweden in 1658, but regained by Denmark in 1660 after a local revolt.