Eusko Gudariak (originally spelt Euzko Gudariak, "Basque Soldiers") was the republican anthem of the Eusko Gudarostea, the army of the Basque Autonomous Government during the Spanish Civil War.
It is also used as an anthem by ETA[1] and the organizations orbiting the Basque National Liberation Movement.
The music is a traditional Basque tune from Araba, named Atzo Bilbon nengoan.
[2] The lyrics were composed in 1932 by José María de Gárate, an officer of the EAJ-PNV.
During the war, Captain Alejandro Lizaso Eizmendi added some verses.