ETA, an acronym for Euskadi Ta Askatasuna, was an armed Basque nationalist and far-left separatist organization in the Basque Country between 1959 and 2018, with its goal being independence for the region. The group was founded in 1959 during the era of Francoist Spain, and later evolved from a pacifist group promoting traditional Basque culture to a violent paramilitary group. It engaged in a campaign of bombings, assassinations, and kidnappings throughout Spain and especially the Southern Basque Country against the regime, which was highly centralised and hostile to the expression of non-Castilian minority identities. ETA was the main group within the Basque National Liberation Movement and was the most important Basque participant in the Basque conflict.

Basque nationalism is a form of nationalism that asserts that Basques, an ethnic group indigenous to the western Pyrenees, are a nation and promotes the political unity of the Basques, today scattered between Spain and France. Since its inception in the late 19th century, Basque nationalism has included Basque independence movements.