Claim: Cristiano Ronaldo plays in international football.

The UEFA Champions League is an annual continental club football competition organised by the Union of European Football Associations -LRB- UEFA -RRB- and contested by top-division European clubs . It is one of the most prestigious tournaments in the world and the most prestigious club competition in European football , played by the national league champion -LRB- and , for some nations , one or more runners-up -RRB- of each UEFA national association . The UEFA Champions League final is the most watched annual sporting event worldwide . The final of the 2012 -- 13 tournament had the highest TV ratings to date , drawing 360 million television viewers .   Introduced in 1992 , the competition replaced the European Champion Clubs ' Cup , or simply European Cup , which had run since 1955 , adding a group stage to the competition and allowing multiple entrants from certain countries . The pre-1992 competition was initially a straight knockout tournament open only to the champion club of each country . During the 1990s , the format was expanded , incorporating a round-robin group stage to include clubs that finished runner-up of some nations ' top-level league . While most of Europe 's national leagues can still only enter their national league champion , Europe 's strongest national leagues now provide up to four teams for the competition , and will provide up to five teams from the 2015 -- 16 season onwards . Clubs that finish next-in-line in each nation 's top level league , having not qualified for the UEFA Champions League competition , may be eligible for the next level UEFA Europa League competition .   In its present format , the UEFA Champions League begins in mid-July with three knockout qualifying rounds and a play-off round . The 10 surviving teams enter the group stage , joining 22 other teams qualified in advance . The 32 teams are drawn into eight groups of four teams and play each other in a double round-robin system . The eight group winners and eight runners-up proceed to the knockout phase that culminates with the final match in May . The winner of the UEFA Champions League qualifies for the UEFA Super Cup and the FIFA Club World Cup .   Real Madrid is the most successful club in the competition 's history , having won the tournament 11 times , including its first five seasons . Spanish clubs have accumulated the highest number of victories -LRB- 16 wins -RRB- , followed by England and Italy -LRB- 12 wins apiece -RRB- . The competition has been won by 22 different clubs , 12 of which have won it more than once . Since the tournament changed name and structure in 1992 , no club has managed consecutive wins ; Milan were the last holders to successfully defend their title , in the 1989 -- 90 season . The reigning champions are Real Madrid , who secured their eleventh title in the competition after defeating Atlético Madrid on penalties following a 1 -- 1 draw in the 2016 final .