Real Madrid will this season attempt to become the first team to retain the Champions League since AC Milan's back-to-back European Cup triumphs in 1989 and 1990.
Victorious for the 11th occasion in the club's glittering history thanks to a penalty shootout success against city rivals Atletico Madrid at San Siro in May, the likes of Barcelona, Bayern Munich and Juventus appear best equipped to challenge Los Blancos.
Paris Saint-Germain and Manchester City continue to search for a breakthrough on the continental stage, while surprise Premier League winners Leicester City get a first taste of the biggest club stage of all.
With the help of Opta, we bring you the some of the key numbers ahead of the 2016-17 group stage draw on Thursday.
10 - In the last 10 seasons of the Champions League, only one team has lifted the trophy without finishing top of their group; Inter in 2010.
5 - Only one country, Spain in 2015, has had five clubs in the group stages. Villarreal's play-off loss to Monaco meant LaLiga failed to match that achievement again this year.
3 - Spanish clubs have won the last three tournaments (Real Madrid in 2014, Barcelona in 2015 and Real Madrid in 2016), the longest run since English clubs claimed six consecutive European Cups from 1977 to 1982.
6 - A 100 per cent win ratio has been achieved six times in a Champions League group-stage campaign, by Real Madrid (2011-12, 2014-15), AC Milan (1992-93), Paris Saint-Germain (1994-95), Spartak Moscow (1995-96) and Barcelona (2002-03, in the first group stage), but none of those teams went on to win the competition.
12 - Napoli failed to progress to the knockout stages of the 2013-14 tournament despite amassing 12 points, the most a team has accumulated without reward. Zenit St Petersburg advanced to the round of 16 in the same campaign with just six points, a joint low together with Roma last season.
17 - Maccabi Tel Aviv in 2015-16 were the most recent of the 17 teams to have lost all six of their Champions League group-stage games. AEK Athens drew all six in the 2002-03 first group stage.
9 - Either Lionel Messi or Cristiano Ronaldo have finished as top scorer in each of the last nine seasons. Neymar was joint top scorer with both men in 2014-15.
2 - Carlo Ancelotti and Bob Paisley are the only managers to have won the European Cup/Champions League three times. The Italian can take the outright lead by guiding Bayern Munich to their sixth triumph, while Pep Guardiola can join them on three with success at Manchester City, who are yet to win the competition.
78 - Luis Enrique of Barcelona has the highest win percentage of any Champions League manager after a minimum of 20 games with 78 per cent. Of the active coaches, Guardiola is next on 62%.
156 & 51 - Former Real Madrid goalkeeper Iker Casillas, now with Porto, has played the most games (156) and kept the most clean sheets (51) in the competition since 1992-93.
