Oslo

Oslo is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2025, while the city's greater urban area had a population of 1,110,887 in 2025, and the metropolitan area had an estimated population of in 2021.
During the Viking Age, the area was part of Viken. Oslo was founded as a city at the end of the Viking Age in 1040 under the name Ánslo, and established as a kaupstad or trading place in 1048 by Harald Hardrada. The city was elevated to a bishopric in 1070 and a capital under Haakon V of Norway around the year 1300. Personal unions with Denmark from 1397 to 1523 and again from 1536 to 1814 reduced its influence. After being destroyed by a fire in 1624, during the reign of King Christian IV, a new city was built closer to Akershus Fortress and named Christiania in honour of the king. It became a municipality on 1 January 1838. The city functioned as the capital of Norway during the 1814–1905 union between Sweden and Norway. From 1877, the city's name was spelled Kristiania in government usage, a spelling that was adopted by the municipal authorities in 1897, although 'Christiania' was also used. In 1925, the city, after incorporating the village retaining its former name, was [|renamed] 'Oslo'. In 1948, Oslo merged with Aker, a municipality which surrounded the capital and which was 27 times larger, thus creating the modern, much larger Oslo municipality.
Oslo is the economic and governmental centre of Norway. The city is also a hub of Norwegian trade, banking, industry and shipping. It is an important centre for maritime industries and maritime trade in Europe. The city is home to many companies within the maritime sector, some of which are among the world's largest shipping companies, shipbrokers and maritime insurance brokers. Oslo is a pilot city of the Council of Europe and the European Commission intercultural cities programme.
Oslo is considered a global city and was ranked as a "Beta World City" by the Globalization and World Cities Research Network in 2008. It was ranked number one in terms of quality of life among European large cities in the European Cities of the Future 2012 report by fDi magazine. A survey conducted by ECA International in 2011 placed Oslo as the second most expensive city in the world for living expenses after Tokyo. In 2013, Oslo tied with the Australian city of Melbourne as the fourth most expensive city in the world, according to the Economist Intelligence Unit's Worldwide Cost of Living study. Oslo was ranked as the 24th most liveable city in the world by Monocle magazine.
Oslo's population was increasing at record rates during the early 2000s, making it the fastest growing major city in Europe at the time. This growth originates primarily from international immigration and related high birth rates, but also from intra-national migration. By 2010 the immigrant population in the city was growing somewhat faster than the Norwegian population, and in the city proper this had become more than 25% of the total population if the children of immigrant parents were included.

Urban region

The municipality of Oslo has a population of 724,290 as of 1 January 2025. The urban area extends far beyond the boundaries of the municipality into the surrounding county of Akershus ; being, to a great degree suburbs of Oslo making up approximately 500,000 of the population of the greater Oslo region. The total population of this agglomeration was 1,546,706 in 2023. The city centre is situated at the end of the Oslofjord, from which point the city sprawls out in three distinct "corridors"—inland north-eastwards, and southwards along both sides of the fjord—which gives the urbanized area a shape reminiscent of an upside-down reclining "Y".
To the north and east, wide forested hills rise above the city giving the location the shape of a giant amphitheatre. The urban municipality of Oslo and county of Oslo are two parts of the same entity, making Oslo the only city in Norway where two administrative levels are integrated. Of Oslo's total area, is built-up and is agricultural. The open areas within the built-up zone amount to.
The city of Oslo was established as a municipality on 3 January 1838. It was separated from the county of Akershus to become a county of its own in 1842. The rural municipality of Aker was merged with Oslo on 1 January 1948. Furthermore, Oslo shares several important functions with Akershus county.

Boroughs	Inhabitants	Area in km²	Number
Alna	50,378	13.7	12
Bjerke	36,460	7.7	9
Frogner	60,646	8.3	5
Gamle Oslo	63,712	7.5	1
Grorud	28,065	8.2	10
Grünerløkka	65,577	4.8	2
Nordre Aker	54,199	13.6	8
Nordstrand	53,969	16.9	14
Sagene	47,660	3.1	3
St. Hanshaugen	40,095	3.6	4
Stovner	34,158	8.2	11
Søndre Nordstrand	39,069	18.4	15
Ullern	35,425	9	6
Vestre Aker	51,869	16.6	7
Østensjø	51,785	12.2	13
Overall	717,710	151.8

In addition is Marka, that is administered by several boroughs; and Sentrum that is partially administered by St. Hanshaugen, and in part directly by the city council. As of 27 February 2020, there were 2,386 residents who were not allocated to a borough.
The nine municipalities directly included in the Urban area of Oslo.

Municipalities	County	Population of the urban area	percentage of population
Oslo	Oslo	705 643	65,2 %
Bærum	Akershus	128 519	11,9 %
Asker	Akershus	71 355	6,6 %
Lillestrøm	Akershus	61 459	5,7 %
Lørenskog	Akershus	46 452	4,3 %
Nordre Follo	Akershus	40 876	3,8 %
Rælingen	Akershus	14 815	1,4 %
Nittedal	Akershus	10 909	1,0 %
Lier	Buskerud	2 547	0,2 %
TOTAL		1 082 575	100,0 %

Name and seal

After being destroyed by a fire in 1624, during the reign of King Christian IV, a new city was built closer to Akershus Fortress and named Christiania in the king's honour. The old site east of the Aker river was not abandoned, however, and the village of Oslo remained as a suburb outside the city gates. The suburb called Oslo was eventually included in the city proper. In 1925 the name of the suburb was [|transferred] to the whole city, while the suburb was renamed "Gamlebyen", literally "the Old town", to avoid confusion.
The Old Town is an area within the administrative district Gamle Oslo. The previous names are reflected in street names like Oslo gate
and Oslo hospital.

Toponymy

The origin of the name Oslo has been the subject of much debate. It is almost certainly derived from Old Norse and was—in all probability—originally the name of a large farm at Bjørvika, while the meaning of that name is disputed. Modern linguists generally interpret the original Óslo, Áslo or Ánslo as either "meadow at the foot of a hill" or "meadow consecrated to the Gods", with both considered equally likely.
Erroneously, it was once assumed that Oslo meant "the mouth of the Lo river", a supposed previous name for the river Alna. Not only has no evidence been found of a river "Lo" predating the work where Peder Claussøn Friis first proposed this etymology, but the very name is ungrammatical in Norwegian: the correct form would have been Loaros. The name Lo is now believed to be a back-formation arrived at by Friis in support of his etymology for Oslo.

Seal

Oslo is one of very few cities in Norway, besides Bergen and Tønsberg, that does not have a formal coat of arms, but which uses a city seal instead. The seal of Oslo shows the city's patron saint, St. Hallvard, with his attributes, the millstone and arrows, with a naked woman at his feet. He is seated on a throne with lion decorations, which at the time was also commonly used by the Norwegian kings.

Other names

Oslo has various nicknames and names in other languages. The city is sometimes known as "The Tiger City", probably inspired by an 1870 poem by Bjørnstjerne Bjørnson which referenced then-Christiania in central Oslo. The nickname is mostly used by Norwegians from out of town, and rarely by people from the Oslo region.

History

Viking Age

During the Viking Age, the area that includes modern Oslo was located in Viken, the northernmost province of Denmark. Control over the area shifted between Danish and Norwegian kings in the Middle Ages, and Denmark continued to claim the area until 1241.
According to the Norse sagas, Oslo was founded around 1049 by Harald Hardrada. Recent archaeological research, however, uncovered Christian burials which could be dated to prior to AD 1000, evidence of a preceding urban settlement. This called for the celebration of Oslo's millennium in 2000 rather than 2049.

1000–1600

Under the reign of Olaf III of Norway, Oslo became a cultural centre for Eastern Norway. Hallvard Vebjørnsson became the city's patron saint and is depicted on the city's seal.
In 1174, Hovedøya Abbey was built. The churches and abbeys became major owners of large tracts of land, which proved important for the city's economic development, especially before the Black Death.
At the end of the 12th century, Hanseatic League traders from Rostock moved into the city and gained major influence in the city.
On 25 July 1197, Sverre of Norway and his soldiers attacked Oslo from Hovedøya.
During the Middle Ages, Oslo reached new heights during the reign of Haakon V of Norway. He was the first king to reside permanently in the city, and it has been regarded as the capital city of Norway since his reign. He also started the construction of the Akershus Fortress and the Oslo Kongsgård.
The Black Death came to Norway in 1349 and, like other cities in Europe, the city suffered greatly. The churches' earnings from their land dropped so much that the Hanseatic traders dominated the city's foreign trade in the 15th century.
In 1380, Norway was the weaker part in a personal union with Denmark, and Oslo's role was reduced to that of provincial administrative centre, with the monarchs residing in Copenhagen.