Basque separatist group ETA is due to announce its final dissolution this week, ending Western Europe's last major armed insurgency, a 50-year campaign which killed more than 850 people in Spain.
Here is a timeline of major events since the founding of ETA, whose initials stand for Euskadi ta Askatasuna (Basque Country and Freedom), and its gradual weakening.
1959 — Students in Madrid form ETA during dictatorship of Francisco Franco, who suppressed Basque culture, to fight for an independent state in northern Spain and southern France.
1968 — ETA carries out first known killing, shooting Melito Manzanas, secret police chief in Basque city of San Sebastian.
1973 — Franco's prime minister and heir apparent Luis Carrero Blanco is killed when his car drives over explosives planted by ETA in Madrid.
1974 — Explosion at Rolando cafe in Madrid kills 12.
1975 — Spain becomes democracy but ETA continues its violent campaign, altering perceptions of movement as force for resistance against fascism.
1978 — ETA founds political wing Herri Batasuna.
1980 — In its bloodiest year, ETA kills about 100 people.
1983 — Government officials set up illegal death squads known as Anti-Terrorist Liberation Groups (GAL).
1985 — ETA car bomb explodes in Madrid. A U.S. tourist is killed and 16 Civil Guards wounded.
1986 — Twelve Civil Guards are killed and 50 wounded in Madrid in July. Juan Manuel Soares is later sentenced to 1,401 years in jail for killings.
1987 — Twenty-one shoppers are killed by bomb at Barcelona supermarket in June. ETA apologises. Car bomb outside barracks in Zaragoza kills 11.
1991 — Ten people killed by car bomb outside Civil Guard barracks in Barcelona.
1995 — ETA members attempt to kill Jose Maria Aznar, leader of right-wing Popular Party, with car bomb. He survives and becomes prime minister in March 1996.
1995 — Attempt to assassinate King Juan Carlos in Mallorca.
1997— Police foil plot to assassinate King Juan Carlos at Guggenheim Museum in Bilbao. One officer dies in shootout, ETA member Eneko Gogeaskoetxea escapes.
1997 — ETA kidnaps and kills Basque Popular Party member and Ermua town councillor Miguel Angel Blanco. Outrage spreads through Spain and 6 million take to streets.
1998 — ETA announces truce which ends in Dec. 1999.
1998 — Former Interior Minister Jose Barrionuevo, his deputy Rafael Vera and a former civil governor, Julian Sancristobal, are jailed for their role in GAL actions. The three were granted a partial pardon and released later that year.
1999 — ETA meets Spanish government in Switzerland. In November, it announces ceasefire for Dec. 3.
2000 — Car bombs in Madrid mark return to violent campaign.
2003 — Supreme Court outlaws Batasuna party, which denies links to ETA but refuses to condemn attacks.
2003 — Two bombs in resort towns of Alicante and Benidorm injure more than 10 people. Santander airport is also bombed.
2004 — Suspected leader Mikel Albisu Iriarte, alias "Mikel Antza" is arrested in France. Prime Minister Jose Luis Rodriguez Zapatero appeals to ETA to give up fight.
2005 — Parliament lower house approves resolution authorising government to negotiate disarmament.
2006 — ETA declares permanent ceasefire in March. Zapatero tells parliament he will seek peace talks. In December, car bomb explodes at Madrid airport killing two Ecuadorians. Zapatero breaks off peace process.
2007 — Zapatero rejects an offer from Arnaldo Otegi, leader of Batasuna, to restart peace talks without demanding major concessions from Spain. In April, ETA says it is willing to compromise if Spain stops arresting militants in Basque Country.
2007 — ETA announces end to ceasefire in June. In December, two undercover Guardia Civil officials are killed in France.
2008 — Zapatero rules out any chance of peace talks with ETA and says only option is unilateral surrender. Isaias Carrasco, former Socialist Party councillor, is killed in Mondragon. In November, ETA claims responsibility for 10 bombings and says it will press its campaign for Basque rights.
— Suspected military leader, Garikoitz Aspiazu Rubina, known by his alias "Txeroki" or "Cherokee", is arrested in France.
— In December, Ignacio Uria, owner of construction company Altuna y Uria which was building high-speed train line, is shot dead in Azpeitia. French police arrest man identified as Balak, presumed successor to Txeroki.
2009 — Jurdan Martitegi, ETA's new military leader known as "the giant", is arrested in France in April. Two Civil Guard officers are killed in explosion at barracks in Mallorca, near royal holiday home, in July.
— French police arrest three suspected members in ski resort and raid 13 weapons stashes in southern France in August, dealing heavy blow to the group.
— In November, Batasuna calls for talks between ETA and Spain based on principles used in Northern Ireland's peace process. Spain rejects overtures the next day.
2010 — Ibon Gogeascoechea, ETA's latest leader and on run since escaping scene of assassination attempt on King Juan Carlos in 1997, is arrested in Normandy.
— French police officer is shot and killed near Paris after suspected rebels fire on his patrol. French Prime Minister Nicolas Sarkozy vows to pursue group.
— Suspected military leader Mikel Kabikoitz Karrera Sarobe, known as "Ata", is arrested in France.
— In September, ETA says it has decided to stop carrying out armed attacks. Spain is sceptical and insists ETA must lay down its arms for good. ETA lays out conditions for end to its violent campaign.
— Batasuna says it will reject violence in its drive to be legalized but government says it must go further to be allowed to participate in elections.
2011 — ETA declares permanent, general and verifiable ceasefire in January. The government rejects it and demands ETA permanently renounce violence and all its activities.
— In October, ETA announces "definitive end" to violence and moves to negotiate with France and Spain, which demand it gives up weapons. ETA makes no mention of possible weapons handover or disbanding.
— ETA says deal with France and Spain would be a condition to end armed fight but Spain says it must disband unconditionally.
2015 — Egoitz Urrutikoetxea arrested in Paris. Incumbent leader Mikel Irastorza arrested in France.
2017 — ETA effectively ends its armed campaign on April 8, surrendering its caches of weapons, explosives and ammunition to authorities in the French city of Bayonne. Spain's government says the move is positive but insufficient, and calls on the group to formally dissolve and apologise to its victims.
2018 — Leaders ask members to vote on whether to dismantle completely by summer after months of internal debate, the group says in February.
— In April, Basque public television reports ETA plans to announce its full dissolution on the first weekend in May. Later the same month, the group apologises for harm caused to victims and their relatives. Spain welcomes the apology, but says it should have been offered a long time before.