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
FC Porto Pinto da Costa assumed Porto's presidency in 1982 and adopted a regionalistic and confrontational speech towards Lisbon. In the following years, the club began establishing its dominance in Portuguese football, at the expense of Benfica and Sporting, who had been the traditional powers since the 1940s. The rivalry with Benfica is the strongest and most passionate, opposing the most representative football emblems from each city as well as the current most titled Portuguese clubs. The first match between Porto and Benfica – traditionally referred to as "O Clássico" (The Classic) – took place on 28 April 1912, and ended with