Pamplona-based Osasuna was founded in 1920 after a merger between Sportiva and New Club, with the team known as Los Rojillos reaching the Segunda Division in 1932 before making it into La Primera for the first time just three years later.
Their stay lasted just one season and it was to be another 17 years before they were back again, with the 1950s and 1960s seeing the club alternate between the top two Divisions.
In the mid-1960s Osasuna moved grounds, selling their old San Juan stadium and moving to the more modern El Sadar, with room for 25,000 spectators, but in 1968 they suffered relegation to the third tier.
The 1970s were spent between this and La Segunda before promotion to the top flight was achieved in 1980, coinciding with the best years in the club’s history.
In 1984 Osasuna qualified for Europe for the first time and the 1990-91 season saw them finish fourth in La Liga under Pedro Mari Zabalza. However, after relegation in 1995 they endured six years in the Segunda Division before regaining top-flight status under Miguel Angel Lotina in 2000, which they have held on to ever since.