ETA violence has gripped Spain since 1968
(CNN) -- The underground group ETA has been committing acts of violence in its campaign for a separate Basque state in northern Spain since 1968.
During that period, ETA has been blamed for killing more than 800 people
Thousands more have been wounded and dozens have been kidnapped by ETA, making the group one of the most feared organizations of its kind in Europe.
It has been designated a terrorist organization by the United States and the European Union.
ETA stands for Euskadi Ta Askatasuna, which means "Basque Homeland and Freedom" in the Basque language. The group was founded in 1959 with the aim of establishing a separate Marxist state in northern Spain and southwestern France.
It began a campaign of deadly violence in 1968, when it killed the police chief in the Basque seaside city of San Sebastian.
ETA has focused its activities on the Spanish side of the border. For many years ETA members found a safe haven in France, a situation that began to change in the mid-1980s, when France began arresting members of the group.
Most of the organization's attacks have targeted politicians, policemen, judges and soldiers, but dozens of civilians have also been killed. In 1987, 21 shoppers were killed in a bombing at a Barcelona supermarket, an attack that long stood as ETA's deadliest.
In 1995, ETA nearly succeeded in assassinating Jose Maria Aznar, the leader of the conservative Popular Party who later went on to become Spain's prime minister. Aznar survived a car bombing because of his vehicle's armor plating.
In 1995, Spanish police also foiled an attempt to assassinate Spain's King Juan Carlos.
On September 16, 1998, ETA declared a "unilateral and indefinite" cease-fire, raising hopes that its campaign was at an end. In June 1999, the Spanish government held its first direct talks with ETA in 10 years, but talks were suspended two months later.
In November 1999, ETA called off the cease-fire and sharply escalated its campaign of violence. Active support for ETA among residents of the Basque region is small, and although no accurate figures are available, its membership is thought to number in the hundreds.
While many Basques support independence, the majority of Basque residents have opposed ETA's use of violence. The Basque region straddles the western end of the Pyrenees in northern Spain and southern France.
Spain officially recognizes three Basque provinces, Alava, Guipuzcoa and Vizcaya. A fourth neighboring province, Navarra, is of Basque heritage. Separatists consider these four provinces plus three in France -- Basse Navarre, Labourd and Soule -- as the Basque region, with a population approaching 3 million.
The area has long possessed a proud sense of cultural independence. The Basque people are considered one of the oldest indigenous ethnic groups in Europe and have lived uninterrupted in the same region since the beginning of recorded history.
In the years before the Spanish Civil War in the 1930s, the Basques of Spain enjoyed a strong degree of autonomy.
Under the fascist regime of Francisco Franco, which lasted from 1939 to 1975, Basque culture, people and language were suppressed, as were regional differences in other culturally distinct parts of Spain. But that changed with Spain's transition to democracy after Franco's death.
The Basque region now has a broad degree of autonomy, with its own parliament, police force and a system of Basque-run schools. Basque is now the region's official language, along with Spanish.