This flag consists of a white cross over a green saltire on a red field.

[1] The original Biscayne spelling of the Aranas was ikuŕiñ (the final -a is the Basque definite article, in singular).

Similar in pattern to the Union Jack, the flag was designed by the founders of the Basque Nationalist Party EAJ-PNV, Luis and Sabino Arana, and is commonly regarded as the national but unofficial symbol of the Basque Country (Euskal Herria).

In 1976, during a derby match between Athletic Club Bilbao and Real Sociedad, players from both teams united to sneak in and display the illegal Basque flag, Ikurrina, at Atotxa Stadium.

The act was successful, as the authorities took no action, and it became a significant step towards the legalization of the flag.