The counties of Sweden (Swedish: Sveriges län) are the top-level geographic subdivisions of Sweden. Sweden is today divided into 21 counties; however, the number of counties has varied over time, due to territorial gains/losses and to divisions and/or mergers of existing counties. This level of administrative unit was first established in the 1634 Instrument of Government on Lord Chancellor Count Axel Oxenstierna's initiative, and superseded the historical provinces of Sweden (Swedish: landskap) in order to introduce a more efficient administration of the realm. At that time, they were what the translation of län into English literally means: fiefdoms. The county borders often follow the provincial borders, but the Crown often chose to make slight relocations to suit its purposes.
In every county there is a county administrative board (länsstyrelse) headed by a governor (landshövding), appointed by the government, as well as a separate regional council (region). In the county of Gotland however, the county's only municipality has adopted regional responsibilities.
The aims of the county administrative board are to supervise local state administration (that is not otherwise assigned to other government agencies), and to coordinate political goals with the central government. The regional council is the elected regional political assembly that oversees the municipal affairs of the county, primarily in regard to public healthcare, public transport, and culture.
Beginning in the 2000s, many major government agencies have reorganised from a countybased subdivisional structure into larger geographical or functional areas. This include the Swedish Tax Agency (1 January 2004), the Swedish Social Insurance Agency (1 January 2005), the Swedish Public Employment Service (1 January 2008), and the Swedish Police Authority (1 January 2015).