A convicted Basque militant has been freed after the Spanish authorities upheld a European Court of Human Rights ruling against her continued detention.
Ines Del Rio, of the separatist group Eta, had been serving a 30-year sentence for bomb attacks in the 1980s.
Spain's High Court had earlier backed the Strasbourg court's ruling against Spanish laws that denied her right to earn remission through prison work.
Spain says dozens of Eta prisoners could now be eligible for release.
Ines del Rio left the Teixeiro prison in A Coruna in north-west Spain at 16:25 local time (14:25 GMT).
Monday's ruling by the European Court of Human Rights "gives us no choice", concluded a prosecutors' report at the High Court requesting Del Rio's immediate release, reported El Pais newspaper.
The penal chamber subsequently ordered her immediate release.
Groups representing victims of Eta's bloody four-decade campaign for independence for regions of northern Spain and south-west France denounced the Strasbourg ruling in protests on Monday, while supporters of the prisoners held marches in favour.
Eta declared an end to its armed campaign in 2011.
Del Rio was arrested in 1987 for her part in 23 murders and car bombings carried out by Eta.
She was later sentenced to more than 3,800 years in jail, but the criminal code in force at the time reduced this to a maximum stay of 30 years.
Del Rio earned sentence reductions through prison work, making her eligible for release in July 2008 - but two years earlier the High Court applied what is known as the "Parot doctrine" to extend her detention.
Under this doctrine, sentence reductions are applied to the sentences for individual crimes - collectively amounting to 3,828 years - rather than the overall 30-year maximum stay.
It meant Del Rio's release would be postponed until 2017.
But on Monday the European Court of Human Rights, upholding a July 2012 ruling in favour of Del Rio, condemned Spain for this practice and ordered Spain to ensure her immediate release and to pay her 30,000 euros (£25,400; $41,000) in compensation.
Although the Strasbourg court's ruling only applies to Del Rio, the Spanish government says dozens of other convicted Eta members could be eligible for release.