[2] Football had been introduced to San Sebastián in the early 1900s by students and workers returning from Britain, and this new sport soon gained a lot of followers in the city and among the young athletes of the Real Club de Tenis, hence the founding of the football section on 28 August 1904, being this the first formally established football club in San Sebastián.

[3] The tournament was played in a triangle format with the finalists of the first-ever Copa del Rey final in 1903, Madrid FC and Athletic Club, the power of Spanish football at the time.

An internal conflict towards the end of 1907 caused the team to split and several players (such as Miguel and Alfonso Sena, Domingo Arrillaga and Bonifacio Echeverría) left to create a new club in 1908, the San Sebastián Football Club, with Federico Ferreirós as its first president.

This team, which continued to play in Ondarreta, adopted the classic blue and white colors of the city flag rather than the striking half-yellow and green shirt of the Recreation Club.

[1] At the time, the teams who had not been legally registered for more than a year could not play official matches, so to play the 1909 Copa del Rey, they borrowed the license from the Club Ciclista de San Sebastián, under whose name they presented themselves and won the tournament.