European club competitions began life in the mid-1950s, with the inauguration of the European Cup and the Inter-Cities Fairs' Cup.
The European Cup, which was rebranded as the Champions League and expanded in 1992, was launched by UEFA. However, participating clubs for the first edition were picked by French newspaper L'quipe. From the second season onwards, it was played by national champions only, plus the holders.
Also in 1955, the Inter-Cities Fairs Cup was inaugurated, initially as the name suggests to promote international trade fairs. After 1964, teams qualified by league position. The competition, which ran until 1971, is considered a precursor to the UEFA Cup (today known as the Europa League). And in 1960, the now-defunct European Cup Winners' Cup was launched.
Here, a look at the biggest winners from the first full decade of European club competitions...
16. Valencia
Valencia were one of three clubs, along with Barcelona and Leeds United, to win the Inter-Cities Fairs Cup more than once.
Champions in 1962 and 1963, Valencia beat Barcelona and Dinamo Zagreb across two legs to claim those two titles, before losing in the 1964 final to Real Zaragoza.
15. Barcelona
Barcelona lost 3-2 to Benfica in the 1961 European Cup final and were edged out by Slovan Bratislava by the same scoreline in the 1969 European Cup Winners' Cup showpiece.
But the Catalan club enjoyed greater success in the Inter-Cities Fairs Cup, winning the competition in 1958, 1960 and 1966 in two-legged finals against a London XI, Birmingham City and Real Zaragoza, respectively. Bara also lost the 1962 final to Valencia.
14. Slovan Bratislava
Slovan Bratislava beat Barcelona 3-2 in Basel to win the European Cup Winners' Cup final in May 1969.
The Sky Blues scored all three of their goals in the first half to lead 3-1 at the break and held on despite Carles Rexach reducing the deficit in the second period. No other club from the former Czechoslovakia (Slovakia or Czechia) has won a European trophy.
13. Bayern Munich
Franz Roth scored the only goal of the game in extra time as Bayern Munich beat Rangers in Nuremberg to claim the European Cup Winners' Cup in May 1967.
Bayern were not yet the dominant force they would become and were without a Bundesliga title since 1932, but this was the beginning of a hugely successful period for the club and young stars such as Gerd Mller, Franz Beckenbauer and Sepp Maier.
12. Borussia Dortmund
Borussia Dortmund beat Bill Shankly's Liverpool 2-1 in the final of the European Cup Winners' Cup at Hampden Park in May 1966.
The match finished 1-1 after 90 minutes, but Reinhard Libuda scored the winner in the second period of extra time as BVB became the first German club to win a European trophy.
11. West Ham
West Ham followed up their 1964 FA Cup success by going on to lift the European Cup Winners' Cup at Wembley the following year.
Two goals from Alan Sealey saw the Hammers defeat 1860 Munich in the final after overcoming Gent, Sparta Prague, Lausanne Sports and Real Zaragoza in the earlier rounds.
10. Sporting CP
After their city rivals Benfica picked up two European Cups in the early 1960s, Sporting Clube de Portugal also got their hands on a continental crown: the European Cup Winners' Cup.
The Lisbon side drew 3-3 with MTK Budapest in Brussels, but beat the Hungarian side 1-0 in the replay in Antwerp two days later, thanks to a goal from Jo�o Morais.
9. Tottenham
Tottenham Hotspur may have been mocked by fans of rival teams for a lack of silverware in recent times, but the north Londoners were the first British club to win a European trophy.
Having controversially lost out to eventual European Cup winners in the semi-finals of that competition in 1962, Spurs went all the way in the European Cup Winners' Cup the following year. The Lilywhites thrashed Atltico Madrid 5-1 in Rotterdam, with two goals apiece from Jimmy Greaves and Terry Dyson and another from John White.
8. Atltico Madrid
Atltico Madrid did not reach a European Cup final until the 1970s, but the Rojiblancos played in two European Cup Winners' Cup finals in the 1960s.
After a 1-1 draw against defending champions Fiorentina at Hampden Park in the 1962 final, Atleti beat the Italian side 3-0 in a replay in Stuttgart to claim the trophy. But a year later, the Madrid outfit were beaten 5-1 by Tottenham in Rotterdam in the 1963 final.
7. Fiorentina
Fiorentina were the first winners of the European Cup Winners' Cup, beating Rangers over two legs in the final in May 1961.
The Serie A side beat the Glasgow giants 2-0 in the first match at Ibrox and won the second leg 2-0 in Florence. Fiorentina reached the final again the following year, losing 4-1 on aggregate to Atltico Madrid. The Viola were also runners-up to Real Madrid in the 1957 European Cup final, which was played at the Santiago Bernabu.
6. Manchester United
A decade on from the Munich air disaster in which eight Manchester United players and three members of the club's staff lost their lives, the Red Devils beat Benfica to win the European Cup.
Manager Matt Busby and captain Bobby Charlton both survived the crash and the pair led United to victory at Wembley. Charlton's opener was cancelled out by a Jaime Graa effort, but Busby's side ran away with it in extra time with three goals within nine minutes from George Best, Brian Kidd and another from the skipper.
5. Celtic
In May 1967, Celtic beat Inter in the European Cup final in Lisbon and became the first British side to win the continent's premier club competition.
Sandro Mazzola gave Inter the lead with a penalty early on, but second-half goals from Tommy Gemmell and Stevie Chalmers saw the Glasgow giants turn the match around. After their victory, that Celtic side became affectionately known as the Lisbon Lions. The Hoops reached the final again in 1970, but lost 2-1 to Feyenoord in Milan.
4. Inter
Inter's first European trophy came in 1964, when the Nerazzurri beat five-time winners Real Madrid 3-1 in the final in Vienna.
A year later, the Milan giants retained their trophy with a 1-0 victory over Benfica as Jair scored the game's only goal at the San Siro. Two years later, the Italians lost 2-1 to Celtic in the 1967 final in Lisbon.
3. Benfica
Benfica won the European Cup in 1961, beating Barcelona 3-2 in an exciting final in Bern.
That was the first final not to include Real Madrid, but Los Blancos were back in the 1962 showpiece. Benfica were too strong for the Spanish side, though, retaining the trophy thanks to a 5-3 win in Amsterdam. The Portuguese giants went on to lose three more finals in the 1960s in 1963, 1965 and 1968.
2. AC Milan
AC Milan have a proud history in the European Cup and the Rossoneri sealed their first title by beating Benfica 2-1 in the 1963 final at Wembley. And six years later, the Italian side claimed the title for a second time with a 4-1 win over Ajax at the Santiago Bernabu as striker Pierino Prati scored a hat-trick.
A year before that second success in the European Cup, Milan also claimed the European Cup Winners' Cup, with Nereo Rocco's side 2-0 winners against Hamburg in Rotterdam. Milan also lost 3-2 after extra time to Real Madrid in the 1958 European Cup final.
1. Real Madrid
Real Madrid dominated the European Cup from the outset, winning the first five editions of the continental competition.
Los Blancos thrashed Eintracht Frankfurt 7-3 in Glasgow in May 1960 to win the trophy for a fifth time. After losing to Benfica in the 1961 final and to Inter in the 1964 showpiece, Madrid won their sixth European Cup with a 2-1 victory over Partizan in Brussels in May 1966.
