The UEFA Champions League is an annual continental club football competition organised by the Union of European Football Associations (UEFA) 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 champions (and, for some nations, one or more runners-up) of the strongest UEFA national associations. 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. [1] 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. [2] The pre-1992 competition was initi...