May, Leinster were crowned champions of the European Challenge Cup after defeating Stade Français 34–13 in the final at their home ground, the RDS Arena. Leinster successfully completed the double on 25 May, defeating Ulster 24–18 in the Pro12 final to claim their third league championship. Leinster continued their success in the 2013–14 season by becoming the first team ever to defend the Pro12 title, topping the league in the regular season and defeating Glasgow Warriors 34–12 in their fifth consecutive Pro12 play-off final and also secured their seventh major title in as many years. Blooding a new generation (2015–2017) Following a remarkable run of seven major trophies in seven years, Leinster's title run came to an end following the 2013–14 season. The 2014–15 season saw a dip in form, with Leinster finishing in fifth place in the league and failing to make the play-offs. Fortunes in the newly formed Champions Cup were better, with the team reaching the semi-final where they were defeated in extra-time by eventual winners, Toulon. At the end of the season, Head Coach, Matt O'Connor, left the club by mutual consent with former club captain, Leo Cullen, being named as his replacement. Cullen then brought in ex-England coach Stuart Lancaster as senior coach at the start of the 2016–17 season, which saw a huge improvement from Leinster as well a big group of young players coming through. Despite playing brilliant rugby all season, Leinster failed to win any silverware, falling short in the Champions Cup semi-final to old rivals Clermont and shocked by the Scarlets in the Pro12 Semi-Final at the RDS. However, there was huge optimism amongst the players and supporters as they believed this was only the start of a new generation and perhaps another era of success. Return to success (2018–present) Starting with the 2017-18 season, Leinster won four straight Pro14 championships. In Europe, they won the 2017-18 Heineken Cup, defeating Racing 92 by a score of 15–12 in the final in Bilbao. They were runners-up in the 2018-19 final, losing 20–10 to Saracens F.C. Leinster were knocked out of the Heineken cup competition in the quarter-finals in 2019-20, and again at the semi-finals stage in 2020-21. The format of the 2021-22 competition was affected by the COVID-19 pandemic. Leinster won their first round matchup with Bath. However, the day prior to Leinster's second match, an away fixture to Montpellier, the EPCR