Prior to the European Cup, there was the Latin Cup. Between 1949 and 1957 the winners of the Spanish, Portuguese, Italian and French leagues took part in the annual competition. Then in season 1956-57 the European Cup started (so a 2 year overlap) which quickly replaced the Latin Cup. The European Cup continued to be dominated by teams from the old Latin Cup until the 25th May 1967, when Celtic became not only the first British team to win it, but also the first non-Latin team to become champions.
Although we were only the third non-Latin team to compete in the final, it started a great run for north-western European teams as we were joined by Dutch, German and English teams in winning 17 out of the next 18 finals (AC Milan triumphed in 1969 and that was it until Juventus won at Heysel in 1985).
The Lisbon Lions were true pioneers who broke the mould and also played football the way it should be played. If we had lost in 1967 then Inter's turgid ultra-defensive Catenaccio style of anti-football may have dominated and been more widely copied, destroying football as an entertaining spectacle.