Watford Football Club is an English football club from Watford, Hertfordshire. Formed as Watford Rovers in 1881, the club entered the FA Cup for the first time in 1886. In the same year, they also entered the county-wide Herts Senior Cup, reaching the final six times over the next ten years. Watford Rovers became West Hertfordshire in 1893, and joined the Southern League for the 1896–97 season. The team started to change from one composed entirely of amateurs to one including paid professionals. In 1898, West Hertfordshire merged with Watford St Mary's to form Watford Football Club.
The club participated in the Southern League from 1896 until 1920, experiencing considerable success. They won six league titles in this period, including the Southern League First Division in 1914–15. After the resumption of Southern League football following a four-year hiatus due to the First World War, Watford missed out on a second consecutive title in 1919–20 on goal average. They joined the Football League Third Division in the 1920–21 season, and following its subsequent reorganisation became founder members of the Third Division South in 1921.
Watford competed in the Third Division South for the next 37 years, with little success. Fred Pagnam finished as the Division's top scorer in 1922–23, the club reached the final of the Third Division South Cup in 1935 and 1937 (winning on the latter occasion), and Len Dunderdale scored 21 goals for Watford in 1938–39 despite leaving mid-way through the season. The team started to progress after the reorganisation of the Football League into four national divisions in 1958. They won promotion to the Third Division in 1960, the Second Division in 1969, and reached the FA Cup semi-final in 1970. However, the league progress was reversed with two relegations over the next five years, and in 1976–77 Watford were briefly bottom of the entire Football League.