Akershus

Akershus (Norwegian pronunciation: [ɑkəʂˈhʉːs] ) is a county in Norway, with Oslo as its administrative centre. Akershus has been a region in Eastern Norway with Oslo as its main city since the middle ages, and is named after the Akershus Fortress in Oslo and ultimately after the medieval farm Aker in Oslo. From the middle ages to 1919, Akershus was a main fief and main county that included most of Eastern Norway, and from the 17th century until 2020 and again from 2024, Akershus also has a more narrow meaning as a smaller central county in the Greater Oslo Region. Akershus is Norway's largest county by population with over 716,000 inhabitants.
Originally Akershus was one of four main fiefs in Norway and included almost all of Eastern Norway. The original Akershus became a main county (Stiftamt or Stift) in 1662 and was sometimes also known as Christiania Stift. It included several subcounties (Amt or Underamt); in 1682 its most central areas, consisting of modern Oslo and Akershus, became the subcounty of Akershus within the larger main county of the same name. In 1842, the capital city of Christiania, which at the time consisted of a tiny part of modern Oslo, became a separate subcounty within Akershus main county. The main county of Akershus was disestablished in 1919, and the subcounty continued as Akershus county (fylke). During its history Akershus (sub) county ceded territory to Oslo several times; Akershus' most central and important municipality, Aker, was transferred to Oslo in 1948. Thus, while modern Akershus' capital is Oslo, Oslo is not located within the modern county itself. In 2020, the county of Akershus was merged into Viken along with the counties of Østfold and Buskerud, but Akershus was reestablished as a county from 2024 with slightly enlarged borders. Modern Akershus borders Oslo, Hedmark, Oppland, Buskerud, Oslo, and Østfold; it also has a short border with Sweden (Värmland).