Sweden–Finland (Finnish: Ruotsi-Suomi, Swedish: Sverige-Finland) is a Finnish historiographical term referring to Sweden from the Kalmar Union to the Napoleonic wars, i.e. from the 14th to the early 19th century. In 1809, the realm was split after the Finnish war. The eastern half came to constitute the autonomous Grand Duchy of Finland, in personal union with Imperial Russia.
The term was coined by Finnish historians during the 1920s, but since then there has been an effort to drop it from professional historiography due to its perceived inaccuracy. However, it is often still used in everyday Finnish speech and taught in schools.
Although the term has didactic merits, for instance when used in conjunction with the term Denmark-Norway, it is misleading because Finland was an integrated part of the realm since the 12th century, whereas Denmark and Norway were two sovereign kingdoms, which were united in 1380.
The eastern and western regions of the realm became united mainly due to trade and settlements via the Åland Islands. A common misconception is that Finland was conquered by Sweden as a result of crusades, which was a myth later used by Finnish nationalists to strengthen the cohesion of Finland after the Finnish Civil War. Crusades probably occurred, but had no decisive significance.
Until 1809 Finland was considered as one of four Swedish lands. However, it was different from Götaland and Svealand, but not all of Norrland, in that Swedish was not the majority language in this part of the kingdom, except for areas along the coastline and amongst the nobility and the urban upper classes.
During the time of the Swedish Empire Sweden–Finland was identical to Sweden proper; other overseas possessions constituted the dominions of Sweden. However, a conceptual distinction was sometimes made between Sweden and Finland already before 1809: for example, in certain 16th century documents, Gustav Vasa occasionally uses the phrases the cities of Sweden and Finland and the cities of Finland and the cities of Sweden, thus implying that the two entities are not identical.[original research?] In this context, however, "Finland" usually referred to the provinces of Finland Proper and Satakunta, not to Tavastia or Karelia.