The club's official history rated 1955–56 as their best season to date. The newly promoted club achieved their highest ever finishing position of sixth in the First Division, reached the 1956 FA Cup Final, and became the first English club side to participate in European competition when they played their opening game in the group stages of the Inter-Cities Fairs Cup. Their only major trophy is the League Cup, which they won in 1963 and 2011; they reached the FA Cup final twice and the final of the Inter-Cities Fairs Cup twice. During the 1990s, they twice won the Associate Members Cup, a competition open to clubs in the third and fourth tiers of English football.