Akershus Fortress, in modernOslo, was the namesake and center of the region of Akershus since theMiddle Ages, and was located within Akershus main county until 1919.
(As of January 1, 2025, the population of Akershus county in Norway is estimated at 740,680 residents. This makes Akershus the largest county in Norway by population)
Akershus (Norwegian pronunciation:[ɑkəʂˈhʉːs]ⓘ)[2] is a county inNorway, withOslo as its administrative centre, though Oslo is not located within Akershus. Akershus has been a region inEastern Norway with Oslo as its main city since theMiddle Ages, and is named after theAkershus Fortress in Oslo and ultimately after the medieval farm Aker in Oslo. From the Middle Ages to 1919, Akershus was a mainfief and maincounty that included most ofEastern 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 theGreater 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 ofEastern Norway. The original Akershus became a main county (Stiftamt orStift) in 1662 and was sometimes also known asChristiania Stift. It included several subcounties (Amt orUnderamt); in 1682 its most central areas, consisting of modernOslo 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 intoViken along with the counties ofØstfold andBuskerud, but Akershus was reestablished as a county from 2024 with slightly enlarged borders. Modern Akershus borders Oslo,Hedmark,Oppland,Buskerud,Oslo, andØstfold; it also has a short border withSweden (Värmland).
As a geographical term the meaning of Akershus has changed over time. Akershus originally primarily referred to Akershus main county, which included most ofEastern Norway, with the exception ofUpper Telemark andBåhuslen (now mainly part of Sweden). The modern Akershus county is a direct continuation of the subcounty of Akershus, created in 1682, and included all of modern Oslo and Akershus. 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. Akershus main county ceased to exist in 1919, after which Akershus in everyday usage became synonymous with the modern county that excluded Christiania. Akershus' most central and important municipality,Aker, was transferred to and merged with Oslo in 1948.
After 1948, the remaining Akershus county is conventionally divided intoAsker andBærum to the west of Oslo,Follo andRomerike.
Embracing numerous suburbs and urban areas of Oslo, notably Bærum and historically Aker, Akershus is one of the most densely populated areas in the country. The main national railway lines into Oslo run through Akershus with many junctions and stations such as Asker,Sandvika, Ski, andLillestrøm. Akershus includes some of the lakeMjøsa and some of the riverGlomma.
The county also includes the historical place Eidsvoll, 48 km north of Oslo, in which the national assembly ratified the Norwegian constitution in 1814.[citation needed] South of Eidsvoll is the international airport,Oslo Airport at Gardermoen. Oslo's previous international airport, Fornebu, is also located in Akershus. The estate of the crown prince is located in Asker (the royal palace is in Oslo).
The main road from continental Europe,E6, enters Akershus in the south, and runs through eastern Oslo, further to Gardermoen, and intoHedmark County on the eastern shores of lakeMjøsa.
E18 enters Akershus in the south-east, merges for a short stretch with E6 at Vinterbro inÅs, before running under central Oslo. E18 then turns south-west through Bærum and Asker before enteringBuskerud County north ofDrammen.
E16 runs from the intersection with E18 in Sandvika into Buskerud County west ofSollihøgda.
All main railways out of Oslo run through Akershus:
Akershus became a fief in the 16th century, and then also included the current counties ofHedmark,Oppland,Buskerud, andOslo, as well as the municipalities ofAskim,Eidsberg, andTrøgstad in the county ofØstfold. In 1662, Akershus became anAmt, and in 1685, Buskerud was separated from Akershus and became anAmt of its own. In 1768, Hedmark and Oppland were also separated from Akershus to becomeOplandenes Amt (and Askim, Eidsberg, and Trøgstad were transferred to Østfold). In 1842, the city of Christiania (Oslo) was made a separateAmt, as well. In 1919, the termAmt was changed toFylke. In 1948, Aker, the greatest and the most populous municipality of Akershus, was transferred to the county of Oslo.
The county is named afterAkershus Fortress. The fortress was built in 1299, and the meaning of the name is "the (fortified) house of (the district) Aker". The name is somewhat misleading now, since the fortress is now outside Akershus (it is in Oslo County since 1842). In fact, the administration of Akershus sits outside the county, as well, in the centre of Oslo.
