The UEFA Champions League, known simply as the Champions League, is an annual continental club football competition organised by the Union of European Football Associations (UEFA). Introduced in 1992, it 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. It is one of the most prestigious tournaments in the world and the most prestigious club competition in European football.

The final of the 2012–13 tournament was the most watched UEFA Champions League final to date, as well as the most watched annual sporting event worldwide in 2013, drawing 360 million television viewers. Before 1992, the competition was officially called the “European Champion Clubs’ Cup”, but was usually referred to simply as the “European Cup”. It 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 and more teams. 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. 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 ten times, including its first five seasons. Spanish clubs have accumulated the highest number of victories (14 wins), followed by England and Italy (12 wins apiece). The competition has been won by 22 different clubs, 12 of which have won it more than once.[9] 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 tenth win in the competition after defeating Atlético Madrid 4–1 in the 2014 Final.