Sunday, December 5, 1976, remains a momentous date in contemporary Basque history on account of the remarkable events that took place in Atotxa Stadium, Donostia-San Sebastián: a key crossroads moment of social, political, and sporting history.

That day, the local soccer team in Donostia, Real Sociedad, took on its main rival, Athletic Bilbao in the classic Basque derby game. However, the moment that really defined the match took place before a ball was even kicked. As the two teams took to the field, the respective captains—Inaxio Kortabarria of Erreala and Jose Angel Iribar of Athletic—led their players into the contest while jointly carrying an ikurriña, the Basque flag, which was at the time an illegal act in Spain.

The flag was sown by the sister of one of the Erreala players, José Antonio de la Hoz Uranga, who himself smuggled it into the stadium that day, even managing to hide the banned symbol from a police check on the way to the game. Having done so, Kortabarria went over to the Athletic locker room and suggested the idea of jointly taking the field by holding the flag, in an act aimed at calling for its legalization over a year after the death of Spanish dictator General Franco. In the end, both captains agreed that all the players competing had to agree with the idea—something, all of them local, agreed to without reservation. In the historic photo that marks that occasion, it is de la Hoz Uranga (who did not play that day) who appears covered by the flag walking between the two captains.

Erreala beat Athletic 5-0 that day, but more importantly, the act of carrying out the ikurriña did much to accelerate the legalization of the Basque flag by the Spanish authorities. Ultimately, its public display was finally legalized on January 17, 1977.

Sport in general, including a special focus on Basque sports, is addressed in the CBS publication Playing Fields: Power, Practice, and Passion in Sport, edited by Mariann Vaczi.