The Champions League is an annual competition organized by the European organization UEFA. This tournament is contested by the best clubs in Europe and it is one of the world's most-watched tournaments.

Each year, some of the world's most famous soccer clubs compete in this competition. It is the hope of any team that participates to win the UEFA Champions League and to write their name on the coveted trophy at least once in their history.

Introduced in 1955 as the European Champion Clubs' Cup, but generally referred to as the European Cup, it was originally a knock-out competition open to domestic European league champions only, with its winner counted as the European club champion. In 1992, it was renamed, introducing a round-robin group stage in 1991 and having several teams from the same country after 1997.

22. Red Star Belgrade

Red Star Belgrade faced French club Marseille in the 1991 European Cup Final, at the Stadio San Nicola in Bari, Italy. Compared to other finals, this game was played only once, on May 29, 1991. Shortly before the break of Yugoslavia, Red Star won the tournament.

Red Star beat Marseille on penalties as the game ended in a 0-0 draw after 120 minutes of action. All five of the Yugoslav side's penalty kicks were converted. Up to date, no other ex-YU country has managed to have a European Cup/Champions League winner yet.

21. PSV Eindhoven

PSV Eindhoven have featured in only one European Cup final, and they managed to lift the trophy. The Dutch side were the better side against Benfica in the 1988 European Cup Final. The clubs faced off on May 25, 1988, at the Neckarstadion in Stuttgart, Germany.

The game finished in a 0-0 draw after extra time, as the winner had to be determined through penalty kicks. PSV Eindhoven scored all six of their penalty kicks, while Benfica scored five. Thus, PSV won the finals 6-5 on penalties. For the first time in 15 years, they became the first Dutch team to win the European Cup.

20. Aston Villa - 1 title

It seems impossible now but Aston Villa managed to beat Bayern 1-0, thanks to a goal by ex-English striker Peter Withe. This final was played on May 26, 1982, at the De Kuip in Rotterdam, the Netherlands.

The English side won their only European Cup soccer club tournament that season, lifting the title out of 33 clubs. It was the sixth straight year the competition was won by an English club.

19. Feyenoord - 1 title

Feyenoord were the better side against Celtic in the 1970 European Cup Final. Marinus Israel (Feyenoord) and Thomas Gemmell (Celtic) were the only goalscorers in the regular time. Bengt Kindvalll scored the winning goal in the 117th minute of the extra time.

The game was played on May 6, 1970, at the San Siro in Milan, Italy. It was the first time a Dutch club won the competition, as well as the first of four consecutive years that Dutch clubs would win the competition.

18.  Borussia Dortmund - 1 title

In a 3-1 final win over reigning champions Juventus, Borussia Dortmund claimed the tournament in the 1996-97 season. The game was played at the Olympiastadion in Munich, Germany, on May 28, 1997. Borussia were the runners-up in the 2013 final.

Karl-Heinze Riedle scored a brace, but Juventus returned in the game thanks to a goal by Alessandro Del Piero. Then Lars Ricken shut down all their hopes, scoring the fourth and the final goal of the game. It was Borussia's only title to date in the tournament and Germany's first title since its 1990 reunification.

17. Marseille - 1 title

Believe it or not, Marseille played a huge part in the European Cup during the '90s. They have won the Cup only once, but they were considered to be very dangerous at the time. They even managed to upset the great Milan in 1993.

The final was played on May 26, 1993, at the Olympiastadion in Munich, Germany. Basile Boli scored the lone winning goal of the game. The French side have also lost one European Cup final, in 1991, against Red Star Belgrade on penalties.

16. Steaua Bucuresti - 1 title

Steaua Bucuresti are one of the many sides who are struggling during this century, but they used to be powerhouses back in the days. They won their first European Cup in the 1985-86 season. The Romanian side were the runners-up several years later, in 1989 when they lost to Milan in the final.

It was on May 7, 1986, when they faced the grand Barcelona at the Estadio Ramon Sanchez Pizjuan in Seville, Spain. The game ended 0-0 in regular time, but Barca players managed to miss all of their penalty-kicks, giving away the title to Steaua.

15. Hamburger SV - 1 title

Hamburger SV faced Juventus on May 25, 1983, at the Athens' Olympic Stadium in Greece. Felix Magath opened the score in the early phase of the game and it proved to be the winning goal.

That was the first time since 1976 that the award had not gone to any English club. Hamburger played another European Cup final earlier in the 1979-80 season, but they failed to win vs Nottingham Forest.

14. Celtic - 1 title

Celtic may have failed to beat Feyenoord in the 1970 European Cup final, but they had already managed to lift the trophy three years earlier. The game was played on May 25, 1967, at the Estadio Nacional in Lisbon, Portugal.

The Scottish club beat Inter 2-1 in the final. Sandro Mazzolla opened the score for the Nerazzuri from the penalty spot. However, Gemmell added a brace to turn the result around and bring Celtic their first and only European Cup trophy.

13. Chelsea - 2 titles

As weird as it sounds, Chelsea aren't even in the Top 10 most successful clubs of all-time in the Champions League. Chelsea have won only one Champions League trophy in their history, in the 2011-12 season. Chelsea were runners-up in 2008 when they lost to Manchester United on penalties.

They faced Bayern on May 19, 2012, at the Allianz Arena in Munich, Germany. Thomas Muller opened the score in the 83rd minute, but it took only five minutes for Chelsea to equalize through Didier Drogba. The Blues went on to become champions, winning 4-3 after a series of penalty-kicks.

12. Porto - 2 titles

Porto have won two European Cup/Champions League trophies so far. Their first victory came on May 27, 1987, when they played against Bayern. The game was set at the Prater Stadium in Wien, Austria. The Portuguese side managed to come from behind in the final and win 2-1.

Led by the great Jose Mourinho, Porto scraped their second title in the final vs Monaco. Carlos Alberto, Deco, and Dmitri Alenichev wrote their name on the scoresheet on May 26, 2004, at the Arena AufSchalke in Gelsenkirchen, Germany.

11. Nottingham Forest - 2 titles

As mentioned above, Nottingham Forest and Hamburger met in the 1980 European Cup final. They faced off at the Santiago Bernabeu Stadium in Madrid, Spain, on May 28, 1980. However, that was actually their second consecutive European Cup title.

The first time they won the trophy was the year before, in 1979. Interestingly, they clashed off against Malmo on May 30, 1979, at the Olympiastadion in Munich, Germany. Trevor Francis scored the only goal of the game back then.

10. Benfica - 2 titles

Another Portuguese side, Benfica have lifted the European Cup trophy on two consecutive occasions. First, they faced Barcelona on May 31, 1961, at the Wankdorf Stadium in Bern, Switzerland. They were the better side against Barca, eventually managing a dramatic 3-2 win.

The second time was during the next 1961-62 season. In that final at the Olympisch Stadion in Amsterdam, the Netherlands, they saw Real Madrid off. The final score was 5-3 and not even Ferenc Puskas' hattrick could prevent the Madrid outfit from losing. In addition, Benfica have lost five finals in their history (in 1963, 1965, 1968, 1988, 1990).

9. Juventus - 2 titles

Juventus were the squad that ended the domination of English side Liverpool in European soccer in 1985 by winning 1-0 in the final. This Juventus team was undeniably the best ever Juventus team which consisted of Paolo Rossi, Zbigniew Boniek, Marco Tardelli, and Michel Platini.

This was the first time in their history that the team had won a Champions League title, 11 years later they did so again to win the 1996 Champions League, making it a record of two, which came close to making it a third in 2015 when they faced Barcelona in the final but the Spanish giants defeated them. In addition, Juve have lost seven other finals (in 1973, 1983, 1997, 1998, 2003, 2015, 2017).

8. Manchester United - 3 titles

In 1968, Manchester United won their first Champions League trophy against Eusebio's Benfica. This trophy came after a difficult time for Manchester United who were building their squad after the 1958 Munich Air disaster. Their second Champions League title came in 1999 when the Red Devils scored two extra-time goals after Bayern led for almost 85 minutes.

The third one came in 2008 when in the final in Moscow they faced fellow English team, Chelsea. Manchester United also participated in three other finals, to no success (in 2009, and 2011).

7. Inter - 3 titles

Many could argue if Inter have always been in the shadow of their arch city-rivals Milan. However, that fact has never overlooked their success in European soccer. The Italian club have won three Champions League/European Cup trophies, two of them coming in the mid-sixties.

They managed to grab two successive European titles in 1964 and 1965, respectively. The third title came under Jose Mourinho, who helped them win a treble, by securing the Scudetto, the Champions League, and the Coppa Italia trophies. Inter also have two failed finals (in 1967,  and 1972).

6. Ajax - 4 titles

In the early 1970s, Ajax managed to do the impossible. They won three straight Champions League trophies in 1971, 1972, and 1973. The Dutch club used to be a force to be reckoned with. Ajax became too good for their opponents led by the irreplaceable Johan Cryuff.

On May 24, 1995, they won their fourth title after beating Milan 1-0 at the Ernst-Happel-Stadion in Wien, Austria. They also have two unsuccessful finals (in 1969, and 1996).

5. Barcelona - 5 titles

Back in 1992, Barcelona vanquished Sampdoria as Johan Cruyff's side first won their first Champions League title. After defeating Arsenal in the final 2-1, they won their second in 2006, ending their 14-year wait for Champions League glory.

With their new coach Pep Guardiola joining the squad and adopting the "Tiki Taka" style with Andreas Iniesta and Xavi managing the midfield, they defeated Manchester United 3-1 in 2009 and again in the final in 2011 (2-0). In 2015, their fifth Champions League came when they defeated Juventus in the final. In addition, Barca have lost three finals (in 1961, 1986, 1994).

4. Liverpool - 6 titles

With 6 Champions League titles, Liverpool is the most successful English side in the Champions League. In the late 70s and early 80s, the Reds were a formidable power, winning four European Cups with great players like Kenny Dalglish and Graeme Souness.

In 1977, Liverpool captured their first trophy in the Champions League. Their second came in 1978, a year after that. They secured their third in 1981 one, got their fourth in 1984. They eventually claimed their fifth in a thrilling final against Milan in 2005. Then in 2019, they clinched their final title, beating Tottenham 3-0 in the final. The Reds ended up runners-up in 1985, 2007, and 2018.

3. Bayern - 6 titles

The current German Bundesliga champions Bayern have won their sixth Champions League title on August 23, 2020. Prior to that, The Bavarians won three straight Champions League titles from 1974-1976. all thanks to the prolific Gerd Muller.

In a 2-1 display down at Wembley Stadium in 2013, Bayern Munich had to wait 25 years to taste Champions League glory once again when they beat fellow German side Borussia Dortmund. Then in 2019-20, they faced Paris Saint-Germain in the final at the Estadio da Luz in Lisbon, Portugal. Bayern also have five failed finals in 1982, 1987, 1999, 2010, and 2012.

2. Milan - 7 titles

With seven Champions League titles, Milan is the second most successful Champions League team. In 1963, when they defeated Benfica 2-1 in the final to win their first Champions League glory ever. Then, after beating Ajax 4-1 in the 1969 Champions League final, they got their second.

Ten years later, in the late 1980s, they won their third, followed by their fourth and fifth in the early 1990s. The Rossoneri won their sixth title in 2003 in an all-Italian final, overcoming Juventus at the Old Trafford in Manchester, England on penalties. In 2007, they managed to get their revenge on Liverpool for the 2005 UCL final. In addition, they have four failed finals (in 1958, 1993, 1995, and 2005).

1. Real Madrid - 13 titles

From 1956 to 1960, Real Madrid won five straight Champions League titles. At the end of the '50s, the Spanish club were dominant in Europe. After crushing Frankfurt 7-3, their most famous triumph came in the final of 1960, when Alfred Di Stefano scored a hat-trick and guided Real Madrid to their fifth Champions League title. The Spanish side won two more UCL titles in 1966 and 1998.

They captured their eighth crown in 2000, and the ninth two years later. In 2014 and 2016, the Whites defeated city rivals Atletico Madrid after extra time to win their tenth and eleventh Champions League respectively.  Their twelfth championship came in 2017 when they won 4-1 against Juventus. In 2018, their 13th win came when they defeated Liverpool 3-1. Madrid also have three unsuccessful finals (in 1962, 1964, and 1981).