Østfold

Østfold (Norwegian pronunciation: [ˈœ̂stfɔɫ] ^ⓘ) is a county in Eastern Norway, which from 1 January 2020 to 31 December 2023 was part of Viken. Østfold borders Akershus and southwestern Sweden (Västra Götaland County and Värmland), while Buskerud and Vestfold are on the other side of Oslofjord. The county's administrative seat is Sarpsborg. The county controversially became part of the newly established Viken County on 1 January 2020. On 1 January 2024, Østfold was re-established as an independent county, however without the former municipality of Rømskog, which was amalgamated with the Akershus municipality Aurskog-Høland in 2020.

Many manufacturing facilities are situated here, such as the world's most advanced biorefinery, Borregaard in Sarpsborg. Fredrikstad has shipyards. There are granite mines in Østfold and stone from these were used by Gustav Vigeland.

The county slogan is "The heartland of Scandinavia". The local dialects are characterized by their geographical proximity to Sweden.

The old name of the Oslofjord was Fold; Østfold means 'the region east of the Fold' (see also Vestfold). The name was first recorded in 1543; in the Middle Ages the name of the county was Borgarsysla 'the county/sýsla of the city Borg (now Sarpsborg)'. Later, when Norway was under Danish rule, the Danish king divided the area into many baronies. These were merged into one county (amt) in 1662 - and it was then named Smaalenenes Amt 'the amt consisting of small len'. The name was changed back to Østfold in 1919.

Østfold is among the nation's oldest inhabited regions, with petroglyphs (rock drawings) and burial mounds throughout the area.

In the Viking Age, the area was part of Vingulmark, which in turn was part of Viken and included Båhuslen (which is now the Swedish province called Bohuslän). It was partly under Danish rule until the time of Harald Fairhair.

Later, when Norway was under Danish rule, the Danish king divided the area into many baronies. The barony of Heggen og Frøland, consisting of the municipalities Askim, Eidsberg and Trøgstad, originally belonged to Akershus - but it was transferred to Østfold in 1768.

In October 2018, Norwegian archaeologists headed by the archaeologist Lars Gustavsen announced the discovery of a buried 20 m (66 ft) long Gjellestad Viking ship. An ancient well-preserved Viking cemetery for more than 1000 years was discovered using ground-penetrating radar. Archaeologists also revealed at least seven other previously unknown burial mounds and the remnants of five longhouses with the help of the radar survey.