Southampton Football Club, an English association football club based in Southampton, Hampshire, was founded in 1885 as St. Mary's Y.M.A. For almost six years the club took no part in any official competitions at national level, playing only friendlies and local tournaments, including the Hampshire Senior Cup. St Mary's first entered the FA Cup in the 1891–92 season, and in 1894 under the name Southampton St Mary's joined the newly founded Southern Football League.
The club changed its name to simply Southampton at the start of the 1896–97 season, and quickly established themselves as the primary force in football in South England, winning the Southern League three times in a row. The club also reached the semi-finals of the FA Cup in 1898, losing the replay 2–0 to Nottingham Forest after a 1–1 draw. The Saints continued to dominate the league into the 20th century, claiming the championship again in 1901, 1903 and 1904, before joining the Football League Third Division as a founding member in 1920, following the absorption of the Southern League. Southampton were almost instantly promoted to the Second Division, completing the feat as champions in the 1921–22 season.
Southampton found life in the second flight of English football difficult, as they remained a mid-bottom table side throughout the seasons played before and immediately after the Second World War, before they were ultimately relegated back to the Third Division in 1953. Promoted as champions again in 1960, Southampton performed well in the following ten years, reaching the quarter-final stage in the newly created League Cup in 1961 and earning promotion to Division One in 1966 as division runners-up. The club received its first taste of continental football in the 1969–70 season when they competed in the Inter-Cities Fairs Cup, although were knocked out in the first round. Despite suffering relegation back to Division Two in 1974, Southampton achieved a surprise victory in the 1976 FA Cup Final against Manchester United to win the trophy for the first and only time in the club's history. This success was topped off two seasons later when the club regained its First Division place.