Porto and Leixões S.C., who were immediately joined by many other clubs, including some from outside districts.
Today it is the largest football district association in the country with 340 clubs and 19.796 athletes in all age categories, 750 referees and organises around games 12.800 per season.
[1] Below the Campeonato de Portugal (Portuguese third level) the competitions are organised at a district level (known in Portuguese as Distritais) with each District Association organising its competitions according to geographical and other factors.
AF Porto runs a league competition with four divisions, at the fourth, fifth, sixth and seventh levels of the Portuguese football league system and a cup competition known as Taça AF Porto (since 2013–14).
Aves, Boavista, Leça, Leixões, Paços de Ferreira, Penafiel, Porto, Rio Ave, Salgueiros, Tirsense, Trofense, Varzim, the forerunners to Felgueiras and the defunct Académico do Porto have competed in Primeira Liga, which at 14 clubs is the highest total for a District Association.