Brøndbyernes Idrætsforening (, usually abbreviated to Brøndby IF (), is a professional association football club based in Brøndbyvester, Capital Region of Denmark. The club was founded in 1964 as a merger between two local clubs and was promoted to the Danish top-flight football league in 1981. Brøndby IF has won 11 Danish championships and 7 Danish Cups. Brøndby's most successful period was from 1985 to 2005 when, in twenty years, they won ten league titles. In 1991, Brøndby reached the semi-finals of the UEFA Cup and became the first and only Danish club to ever reach a European semi-final. Since the founding of F.C. Copenhagen in 1992, they have had a fierce rivalry. Matches between the two clubs are referred to as the Copenhagen Derby. History Formation (1964–1977) Brøndbyernes Idrætsforening was formed on 3 December 1964 following a merger between two local rivals – Brøndbyøster IF and Brøndbyvester IF. The merger was to be completed as a prerequisite for the construction of a new stadium by Brøndby Municipality. Brøndby IF spent its inaugural season as an amateur club in the 6th tier of the 11 Danish leagues, the Serie 1, where they finished their two first seasons in fourth place. Among the players of the early years was team captain Per Bjerregaard, a doctor who had moved to Copenhagen from Randers in Jutland, and Hans Gregersen, who was the mascot of the team until his death by syphilis in 1967. In 1967, the club hired coach Leif Andersen who instantly secured promotion to Sjællandsserien (the Zealand series). After a few mediocre years, a new coach, John Sinding, was brought in, and the club won promotion to Danmarksserien (the Denmark series). In 1973, Per Bjerregaard stopped his active career at 27 years of age and became chairman of Brøndby; his first action was to sack head coach Sinding. In his place, Brøndby hired former professional and Denmark national team player Finn Laudrup, who took over as head coach while he still took actively part in the matches as a player. Laudrup joined his brother-in-law Ebbe Skovdahl in the Brøndby team, and he brought his two young sons Brian and Michael Laudrup with him to the club. Under Finn Laudrup's influence, the club's playing style was changed to a more attacking strategy, even though Laudrup decided to fully concentrate his efforts as a player after only a year. After winning promotion in