Between 1896 and 1920, West Herts (and later Watford) competed in the Southern League, along with many future Football League sides from Southern England and Wales. The team won the league title in 1914–15, and finished as runners-up to Portsmouth on goal average in 1919–20. Watford joined the Football League in 1920, and since then have won the Third Division twice,[n 1] and the Fourth Division once. They have achieved promotion to the top level of English football on four occasions; as runners-up of the Second Division in 1981–82, and winners of the play-off final (often considered the richest game in football)[1] in 1999 and 2006. They also gained automatic promotion in 2015, finishing second in the Championship. Their highest finish in the Football League was second in the First Division, achieved in 1982–83.
Watford's best performances in the FA Cup came in the 1984 FA Cup and 2019 FA cup, when they reached the final whilst suffering the biggest ever score line defeat in 2019. They have reached the semi-finals on four further occasions, and have also reached the semi-finals of the Football League Cup twice. On Watford's only appearance in a major European cup competition to date, they reached the third round of the UEFA Cup in 1983–84. They also won the Third Division South Cup in 1937; which was shared with Millwall after being level 3–3 over two legs.
