To achieve the "treble" - a task that is perhaps the most difficult in European football.
The "treble" consists of the UEFA Champions League, local cup, and local championship titles. All of these trophies must be won in a season in order to be called the winners of the "treble."
Throughout European football history, only 8 clubs have achieved this feat.
The only club to have done it twice is "Barcelona" and Munich's "Bayern." Speaking of the latter club, this achievement was accomplished in the 2012-13 and 2019-20 seasons. The first time they beat the "Stuttgart" team in the local DFB Pokal final, and the second time they faced off against Leverkusen's "Bayer" club. Meanwhile, in the Champions League finals, Dortmund's "Borussia" (2012-13) and PSG (2019-20) fell under the Bavarians.
"Barcelona" dominated in Europe in the 2008-09 and 2014-15 seasons, confidently winning three trophies. The first time they surpassed "Manchester United" in the Champions League final, and the second time - the "Juventus" team. In the Spanish cup final, both times the Catalans could not withstand Bilbao's "Athletic."
"Manchester City" also achieved the "treble" last year, defeating "Brighton" in the FA Cup final and beating the "Inter" team in the Champions League final.
Interestingly, the list does not include the 14-time Champions League champions and 35-time Spanish champions Real Madrid. They never seemed to draw a lucky card to add a new achievement to the club's history. The closest they got was in the 2016-17 season when they narrowly missed the Copa del Rey title.
Other clubs that have won the "treble" include "Inter," "Manchester United," PSV, "Ajax," and "Celtic."