S.L. Benfica 2015, Benfica reported to have 246,401 members; however, after a scheduled renumbering by the club in August 2015, the number decreased to 156,916. In April 2017, Benfica reported they had a total of 184,264 members by 31 December 2016. Benfica has rivalries with Sporting CP and FC Porto, with whom it forms the "Big Three": Portugal's most decorated clubs. None of them have been relegated from the Portuguese league since its establishment in 1934. As Lisbon-based clubs, Benfica and Sporting have shared a rivalry for over a century; it all started in 1907 when eight prominent Benfica players defected to
1990–91 S.L. Benfica season attentions were pointed on the league title. A strong campaign witnessed Benfica overtake Porto in February and then close the title with an away win in the Clássico, a controversial match because of the tactics employed by Porto to destabilize the team. On late May, Benfica secured their 29th league title, while Rui Águas won the Bola de Prata for league top-scorer. Benfica started the new season after having lost their fifth European Cup Final in the past season, while Porto regained the league title back. Swedish manager Sven-Göran Eriksson made some squad adjustments, releasing established players like Fernando Chalana,