Kortatu was one of the most influential and pioneer bands in the Basque punk-ska movement. Considered the Basque "Clash", Kortatu mixed the speed of punk with two-tone's rhythms, creating a fast, active and unique punk-ska. Kortatu was one of the groups known as "Rock Radikal Vasco" (Basque Radikal Rock). They originally sang in Spanish but eventually changed to Euskera (Basque). Founded in Irun in 1984 by Fermin Muguruza, Iñigo Muguruza and Treku Armendariz. Kaki Arkarazo joined the band in its last years.