Wikipedia
Tippeligaen is a Norwegian professional league for association football clubs. At the top of the Norwegian football league system, it is the country's primary football competition. The league is also unofficially known under its neutral name (English: The Elite League).
Before 1937, there was no national league competition in Norway; only regional leagues and the Norwegian Cup. Starting in 1937–38, the various regional leagues in Southern Norway were aligned into eight districts, with a championship playoff between the winners to crown a national champion. This competition was called Norgesserien (English: The League of Norway). There were plans at the time to merge the district leagues into a national competition, but because of World War II, this process was delayed until after the war.
In 1948, Hovedserien (English: The Main League) was created, consisting of the 16 top teams from the district leagues, who were placed into two groups of eight, with the group winners playing for the national championship at the end of the season. This format was in place from the 1948–49 season until 1960–61, when it was decided to merge the two groups into a single top division, and have the season follow the calendar year from 1963 onwards. The 1961–62 season became a transitional season, where the 16 top-flight teams were placed in a single group, playing a season that lasted 18 months. Officially still known as Hovedserien, the 1961–62 season became informally known as Maratonserien (The Marathon League) because of its unusual length.
In 1963, a single top division containing ten teams was introduced, and the league was renamed 1. Divisjon (English: 1st Division). The league was expanded to 12 teams in 1972. In 1990, the league was renamed Tippeligaen, after Norsk Tipping which has been the main sponsor of the league since then. However, unofficially the league was still known as 1. Divisjon by most people. And ahead of the 1991-season it was decided to let the second level league of Norwegian football "inherit" the name 1. divisjon to help Tippeligaen establish as a brand. In 1995, Tippeligaen was expanded to 14 teams, and in 2009 it was further expanded to 16 teams.
An important note is that teams from Northern Norway were not allowed to gain promotion to the top division before 1972. In 1979 teams from Northern Norway were given the same promotion rights as the rest of the country.