Which league has the only team to complete a treble (domestic league, domestic cup, and UEFA Champions League) more than once?

Which league is home to the only team to have won six trophies in a single calendar year (a sextuple)?

Which league's teams have the most UEFA Europa League titles combined?

Which league has the only team that has never been relegated since its formation?

Which league's teams have scored the most goals in UEFA Champions League history?

Which league’s team holds the record for the longest unbeaten home run in domestic league history?

Which league is home to the only team to have won the UEFA Champions League three times in a row since the competition was rebranded?

Which league’s team holds the record for the fastest-ever goal scored in a domestic league match?

Which league was the first to introduce VAR (Video Assistant Referee) in a full season of its domestic competition?

Which league’s teams have won the most UEFA Champions League titles combined?