The competition began as the Heineken Cup in 1995 with twelve clubs from Ireland, Wales, Italy, Romania and France. English and Scottish teams didn't take part in the inaugural competition which was won by Toulouse who beat Cardiff in extra time at Cardiff Arms Park.
English and Scottish teams joined the Heineken Cup in 1996-97 with the European Challenge Cup organised for teams that failed to qualify for the Heineken Cup. Brive won the competition after beating Leicester 28-9 at Cardiff Arms Park and was viewed by approzimately 35 million people in 86 countries.
The 1997-98 Heineken Cup was altered with clubs playing in a home and away format in the pool games. Brive were beaten by Bath in the Final, but the competition was marred by English clubs withdrawing because of a dispute over the way the competition was being run.
English clubs continued to withdraw in the 1998-99 Heineken Cup tournament that saw 16 teams take part. French clubs dominated the competition, finishing first in three of the four groups.
Colomiers reached the final but were beaten 21-6 by Ulster at Lansdowne Road in Dublin. Ulster had beaten fellow French clubs Toulouse and Stade Français on their way to the final.
English clubs returned to the Heineken Cup in 1999-00 as clubs from four different nations reached the semi-finals (England, Ireland, France, Wales). Munster took on Northampton in the final with Northampton coming out on top 9-8 at Twickenham in London.
The 2000-01 final saw Leicester beat Stade Français 34-30 at Parc des Princes, Paris. From 2002 the European Challenge Cup winner automatically qualified for the Heineken Cup.
In 2003-04 the Welsh Rugby Union (WRU) created regions to play in the Celtic League which meant they could represent Wales in European competitions. Wales would then enter regional sides instead of club sides that had previously competed in the competitions.
The 2004 Heineken Cup final saw Wasps beat Toulouse 27-20 at Twickenham in London. Toulouse won the 2005 Heineken Cup Final 18-12 against Stade Français at Murrayfield in Edinburgh, the first Scottish venue to host the final. Toulouse became the first team to win three Heineken Cup titles.
The 2006-07 Heineken Cup was a breakthrough for the competition in terms of exposure, Pitch International's securing the rights that means the Heineken Cup would be televised in over 100 countries. Wasps won the final 25-9 in front of a tournament record 81,076 fans at Millennium Stadium, Cardiff.
During competition there was uncertainty over the future of the tournament after the 2006–07 season as French clubs had announced that they would not take part because of fixture congestion following the Rugby World Cup and an ongoing dispute between English clubs and the RFU.
Leinster won the 2009 Heineken Cup final after beating Leicester Tigers 19-16 at Murrayfield Stadium in Edinburgh. Toulouse defeated Biarritz Olympique 21-19 in the 2010 Heineken Cup final to claim their fourth title, a then Heineken Cup record.
Leinster won back-to-back titles after beating Ulster 42-15 in the 2012 Heineken Cup final at Twickenham, the highest Heineken Cup final winning margin. The the last edition of the tournament known as the Heineken Cup was in 2004, Toulon beating Saracens 23-6 in the final at Millennium Stadium in Cardiff.
The European Rugby Champions Cup began on 17 October 2014 and replaced the Heineken Cup. Toulon retained the title after beating Clermont 24-18 in a repeat of the 2013 Heineken Cup Final at Twickenham in London, becoming the first club to win three successive European titles.
Saracens won their first European Rugby Champions Cup after a 21-9 win against Racing 92 at Parc Olympique Lyonnais in Décines-Charpieu, France. Saracens followed up with their second European Rugby Champions Cup in 2017 after, beating Clermont 28-17 at Murrayfield in Edinburgh.
Leinster produced a fabulous 2017-18 season, beating Glasgow Warriors, Montpellier and Exeter home and away before beating back to back Champions Saracens to reach the semi-finals. Leinster defeated Scarlets and won 15-12 against Racing 92 in the Champions Cup Final at San Mamés in Bilbao. Leinster also won the Pro14 title to become the first Pro14 side to win the double.
Saracens got their revenge in the 2018-19 European Rugby Champions Cup, defeating defending champions Leinster 20-10 in the final at St James' Park in Newcastle. Saracens were found to be in breach of the Premiership salary cap for the 2017-18 and 2018-19 seasons but it didn't affect the results.
Toulose won the first European Rugby Champions Cup when it was known as the Heineken Cup. The French club have won four titles, the same number as Leinster who last lifted the European Rugby Champions Cup in 2018.