At the end of the 1950s, few believed in oil and gas riches along the Norwegian coast. Little did we know how significant the petroleum industry would become for the Norwegian economy when the first extraction permits were awarded in the mid-1960s. 50 years later, the industry is Norway's most important both in terms of income to the treasury, investments and share of total value creation. In a letter to the Ministry of Foreign Affairs in February 1958, the Geological Survey of Norway wrote "One can ignore the possibility that there would be coal, oil or sulfur on the continental shelf along the Norwegian coast." The event that opened people's eyes to the fact that there could be hydrocarbons in the North Sea was the Dutch discovery of gas in Groningen in 1959. This discovery led to enthusiasm in a part of the world where energy consumption was largely based on coal and imported oil. In the eagerness to find more, attention was directed to the North Sea. Norway's geological expertise was negative for oil and gas deposits, but this could not stop the enthusiasm after the gas discovery in the Netherlands. In October 1962, Phillips Petroleum sent a letter to the authorities in Norway for permission to explore in the North Sea. The company would have a license for those parts of the North Sea which were on Norwegian territory and which would possibly come under the Norwegian continental shelf. The offer was 160,000 dollars per month. The offer was seen as an attempt to obtain exclusive rights. It was out of the question for the authorities to hand over the entire shelf to a company. If the areas were to be opened for exploration, several companies would have to enter. In May 1963, the Gerhardsen government proclaimed Norway's sovereignty over the Norwegian continental shelf. New law stated that the state was the landowner and that only the King (the government) could grant permits for exploration and extraction. The companies were given the opportunity to carry out preparatory investigations in the same year. The permits gave, among other things, the right to seismic surveys, but not to drilling. Although Norway had proclaimed national sovereignty over large sea areas, some important clarifications remained regarding the division of the continental shelf, primarily with Denmark and Great Britain. Agreements on the division of the continental shelf according to the center line principle were concluded in March 1965. The first round of licenses was announced on 13 April 1965. 22 extraction licenses for 78 blocks were awarded to oil companies or groups of companies. The extraction permits gave the exclusive right to explore, drill and extract in the concession area. The first exploration well was drilled in the summer of 1966, but proved to be dry. The first oil discovery made on the Norwegian continental shelf was Balder in 1967. However, the discovery was not profitable enough at the time, and it would take 30 years before the discovery was developed. The Norwegian oil adventure began in earnest with the discovery of Ekofisk in 1969. On Christmas Eve 1969, Phillips informed the Norwegian authorities of the discovery of Ekofisk - what would turn out to be one of the largest oil fields ever found offshore. Production from the field took 15 June 1971. In the following years, a number of major discoveries were made. In the 1970s, exploration activities were concentrated around the areas south of Stadt (62 degrees north). The socket was gradually opened and only a limited number of blocks were announced in each concession round. The areas that seemed most promising were investigated first. This led to world-class discoveries, and production from the Norwegian continental shelf has been dominated by large fields such as Ekofisk, Statfjord, Oseberg, Gullfaks and Troll. These fields have been, and still are, very important for the development of the petroleum business in Norway. In connection with the development, infrastructure was established to which several fields have been able to connect. Now production from several of these fields is decreasing, while several new, smaller fields have been added. Therefore, today's production is distributed over more fields than before. In 1979, petroleum operations were also opened north of the 62nd parallel. Exploration activity in parts of the Norwegian Sea and the Barents Sea began in the early 1980s, and was later expanded as new sea areas were opened up for petroleum activities. Production in the Norwegian Sea started in 1993 and in the Barents Sea in 2007. In the initial phase, foreign companies dominated the exploration business and were responsible for the development of the first oil and gas fields. Gradually, Norwegian involvement increased as Norsk Hydro came on board. So did Saga Petroleum, a private Norwegian company that was established in 1972. In the same year, Statoil was also established with the state as sole owner, and a principle of 50 percent state participation in each extraction permit was established. From 1 January 1985, the petroleum operations were reorganised. The state's participation share was divided into two, one related to the company and one related to the state's direct financial involvement in the petroleum business (SDØE). SDØE is an arrangement where the state owns a share in a number of oil and gas fields, pipelines and land facilities. The share is determined by the allocation of extraction permits and the size varies from field to field. As one of several owners, the state covers its share of investments and costs, and receives a corresponding share of the income from the extraction permit. Statoil took care of the commercial aspects of SDØE on behalf of the State. In the spring of 2001, the Storting decided that 21.5 per cent of the value of the SDØE shares could be sold. 15 per cent was sold to Statoil and 6.5% was sold to other licensees. The sale of SDØE shares to Statoil was seen as an important element in carrying out a successful IPO and privatization of Statoil. Statoil was listed on the stock exchange in June of the same year and now operates on the same lines as any other player on the Norwegian continental shelf. The state limited company Petoro was established in May 2001 to take care of SDØE on behalf of the state. In 2007, Statoil merged with the oil and gas operations of Norsk Hydro. In 2018, Statoil changed its name to Equinor. At the turn of the millennium, it was opened for participation from several types of companies on the continental shelf. For reasons of good resource management, the large international companies that were established in Norway were supplemented by other types of companies that saw other business opportunities in the Norwegian petroleum resources. Today, there is a great degree of diversity and competition on the Norwegian continental shelf with Norwegian and foreign companies active on the continental shelf. The petroleum industry has had a lot to say for economic growth in Norway, and for the financing of the Norwegian welfare society. Little did we know how significant this industry would become for the Norwegian economy when the first extraction permits were awarded in the mid-1960s. The development in the petroleum sector's share of total value creation, investments, exports and income in Norway is a clear picture of this. Activity on the NCS will continue to be of great importance to the Norwegian economy in the future, thanks to large remaining resources and significant new development projects such as Johan Sverdrup.