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
1978–79 S.L. Benfica season first place with 16 points, one more than Porto. Benfica winning run ended on 21 January with a 1–1 draw against Porto on match-day 17. Mortimore complained of a three-meter off-side in Porto's goal. It left Porto in a lead with a game more, because Benfica's match against Académico de Viseu on 30 December had to be postponed due to stormy weather. In February, Benfica was knocked-out of the Portuguese Cup with a 2–1 loss with Braga, a defeat that Mortimore rated as fair. A week later, another defeat, now for the Primeira Divisão. Benfica lost 2–1 in Barreiros to