Armed Basque separatist group ETA said it will end its 15-month-old ceasefire at midnight on Tuesday.
Following is a chronology of some major events since the Euskadi ta Askatasuna (ETA) was founded:
1959 - ETA, or Basque Homeland and Freedom, is founded during dictatorship of General Francisco Franco to fight for Basque self-determination.
1968 - ETA carries out first killing: victim is Meliton Manzanas, police chief in Basque city San Sebastian.
1973 - Franco's Prime Minister Luis Carrero Blanco killed when car passes over explosives planted by ETA in Madrid.
1980 - ETA's bloodiest year, nearly 100 killed, despite Spain's recent return to democracy.
Sept 1985 - First ETA car bomb in Madrid. U.S. tourist killed, 16 Civil Guards wounded.
July 1986 - Twelve Civil Guards killed in Madrid and 50 injured. Juan Manuel Soares, a repentant Basque separatist, is sentenced to 1,401 years in jail in April 2000 for the killings.
June 1987 - 21 shoppers killed by bomb at Barcelona supermarket. ETA apologizes.
April 1995 - Popular Party opposition leader Jose Maria Aznar, later to become prime minister, is target of ETA car bomb. Saved by vehicle's armor plating.
Sept 1998 - ETA announces truce.
Nov 28, 1999 - ETA announces ceasefire to end on Dec 3.
Nov 21, 2000 - Former Socialist health minister Ernest Lluch shot dead in Barcelona. Nearly a million demonstrate.
2004 - ETA calls for dialogue with Spain's incoming socialist government but pledges to maintain its armed campaign.
-- Oct 10 - New socialist Prime Minister Jose Luis Rodriguez Zapatero appeals to ETA to give up the fight after the arrest of its suspected leader, Mikel Albisu Iriarte, alias "Mikel Antza".
Feb 2005 - Spain's parliament rejects Basque premier Juan Jose Ibarretxe's plan for virtual Basque independence.
-- May 6 - Spain's High Court sentences two ETA members to 2,775 years each in prison for the Christmas 2003 plot to plant bombs on a Madrid-bound train.
-- May 17 - Parliament gives Spain's government permission to open peace talks with ETA if it lays down its arms.
March 22, 2006 - ETA declares permanent ceasefire, which comes into force two days later.
-- June 29 - Zapatero tells parliament he will seek to start peace talks with ETA.
-- Dec 30 - Car bomb explodes at Madrid's airport killing two Ecuadorians and forcing Zapatero to break off peace process.
January 9, 2007 - ETA claims responsibility for airport bomb, adds its March declaration of a permanent ceasefire stood.
January 13 - Hundreds of thousands of Spaniards march through major cities for peace, two weeks after the car bomb.
February 25 - Arnaldo Otegi, leader of the ETA-linked Batasuna party says that ETA will not demand major concessions from Spain to restart abandoned peace talks.
-- Zapatero dismisses the offer and says ETA and its supporters had to convince Spain they had given up violence.
April 8 - ETA says it is ready to make new commitments to the troubled peace process if Spain stops its "attacks" in the Basque region where police have been arresting ETA suspects.
June 5 - ETA says it will end its 15-month-old ceasefire.