ETA, an acronym for Euskadi Ta Askatasuna ("Basque Homeland and Liberty" or "Basque Country and Freedom"), was an armed Basque nationalist and separatist organization in the Basque Country (in northern Spain and southwestern France). The group was founded in 1959 and later evolved from a group promoting traditional Basque culture to a paramilitary group engaged in a violent campaign of bombing, assassinations, and kidnappings in the Southern Basque Country and throughout Spanish territory. Its goal was gaining independence for the Basque Country. ETA was the main group within the Basque National Liberation Movement and was the most important Basque participant in the Basque conflict.

Between 1968 and 2010, it killed 829 people (including 340 civilians) and injured thousands more. ETA was classified as a terrorist group by Spain, France, the United Kingdom, the United States, Canada and the European Union. This convention was followed by a plurality of domestic and international media, which also referred to the group as terrorists. There are more than 260 imprisoned former members of the group in Spain, France, and other countries.ETA declared ceasefires in 1989, 1996, 1998 and 2006. On 5 September 2010, ETA declared a new ceasefire that remained in force, and on 20 October 2011, ETA announced a "definitive cessation of its armed activity". On 24 November 2012, it was reported that the group was ready to negotiate a "definitive end" to its operations and disband completely. The group announced on 7 April 2017 that it had given up all its weapons and explosives. On 2 May 2018, ETA made public a letter dated to 16 April 2018 according to which it had "completely dissolved all its structures and ended its political initiative".ETA's motto was Bietan jarrai ("Keep up on both"), referring to the two figures in its symbol, a snake (representing politics) wrapped around an axe (representing armed struggle).