The 1928-1929 season went down in history as the first Spanish football League while the 1929-1930 as the first double rojiblanco triumph. At first, the birth of the regularity tournament was the subject of harsh criticism, faced with the idea that the event could bore fans due to the accumulation of matches; nothing further from reality.
This competition soon left behind the interest provoked by regional championships, friendly matches, European tours, etc., to become a point of reference each season. A League which had started out with ten teams, the nine that had previously disputed a Copa final (the Basque teams of Arenas de Getxo, Real Sociedad, and Real Union of Irun, the Catalans F.C. Barcelona, RCD Español and Europa, and the Madrilenians Real Madrid and Athletic Club Madrid), in addition to the champions of a knock-out competition between the teams provisionally designated to form the Second Division (Racing de Santander).
Coinciding with the start of the Liga, the rojiblanco club reunited one of the better squads in its history which, without a doubt, which achieved more victories: 4 League titles, 4 Copa, 6 Regional Championships and 2 Basque Cups. We are talking about 16 official titles in 8 years. It was a time of victories and records, some of which have not been broken to date. A truly glorious and intense stage in Athletic's history, that launched its members into football stardom, as well as their coach Mr. Pentland, along with Blasco, Castellanos, Urkizu, Garizurieta, Mugerza, Unamuno, Lafuente, Iraragorri, Chirri, Bata, Gorostiza, Roberto and Cilaurren, are still prevalent in the memory of the fans.
It was a team made up by, as would be the standard, members from Athletic's lower ranks and home-grown Biscayan players. That's how the following were drafted: Blasco (1926) from the Acero, Unamuno (1927) and Roberto Echevarria (1928) from Alavés, Lafuente (1927) and Bata (1929) from Barakaldo, Gorostiza (1929) and Cilaurren (1932) from the Arenas...with Chirri (1925), Garizurieta (1927), Ispizua (1928) or Iraragorri (1929) coming from the Athletic reserves team.
The English "Mister", Fred Pentland, deserves a separate mention as part of this great team; the manager who, in his two phases (1922-1925 and 1929-1933), obtained the most official titles for Athletic Club, 12 altogether. With his cigar and bowler hat, he was an authentic celebrity in pre-war Bilbao. This team did not play together very long, in any case, the historic forward line of Lafuente, Iraragorri, Chirri, Bata and Gorostiza, the physical qualities of the great defence Leonardo Cilaurren, or the guarantee Blasco the goalkeeper -all of them internationals-, remain in the memory of fans.
By this time, football was already something completely professional, Athletic players received an average of 750 pesetas a month and 20 duros (5 pesetas) for each match won. Only the great Carmelo Goyenechea (who retired after the 1928-29 season) continued as an amateur, anachronistic reflection of past times. The team's pace was fundamental to the economy of the Club, money was only received via fees and tickets, therefore, in the glorious season of 1929-30 a surplus of 172,482 pesetas was obtained which the Board of directors destined to the expansion of the San Mamés grandstand by 400 spectators. Subsequently, more difficult years arrived, in which the Board of Directors invented the Day of the Club (General Assembly of 22 July 1932) so as to not have to sell its talents. Spectators continued attending San Mamés. By 1934, the club already had 4,044 members.
The end of this cycle was quick, abrupt, and definitive due to the war, while the desired transition between generations did not take place due to the conflict.