The Basque separatist group ETA announced on Wednesday its official dissolution, marking an end to its deadly independence campaign. "ETA has decided to declare its historical cycle and functions terminated, putting an end to its journey," the group said in a letter published Wednesday by Spanish online newspaper El Diario. "ETA has completely dissolved all of its structures and declared an end to its political initiative." The letter was dated April 16 and addressed to various groups and figures involved in recent peace efforts, including former UN secretary general Kofi Annan, a Basque regional government representative told AFP. He expected ETA to make a further direct declaration of its disbandment on Thursday, probably in a video. Created in 1959 at the height of Francisco Francos dictatorship, ETA waged more than four decades of attacks, killings and kidnappings in its fight for an independent Basque homeland in northern Spain and southwest France, leaving at least 829 dead. International mediators are organizing a peace conference in southwest France on May 4. Weakened in recent years by the arrests of its senior leaders, ETA (Euskadi Ta Askatasuna, or Basque Country and Freedom) declared a ceasefire in 2011 and handed over weapons in April 2017, bringing Western Europe’s last major armed insurgency to a close. But as it turns the page, the delicate balancing act of healing and remembering takes over. As more and more ETA prisoners are released from jail, nationalists say reintegration into society is a necessary step towards lasting peace and reconciliation. They argue that those still in jail should be transferred to prisons closer to home, rather than kept hundreds of kilometers away. Some 300 ETA members are imprisoned in Spain, France and Portugal and up to 100 are still on the run, according to Forum Social, a group close to prisoners families. Northern Irelands Gerry Adams, the former head of Sinn Fein -- once the political wing of the Irish Republican Army -- called on Spain and France to build on ETAs "initiatives" in a statement published ahead of his trip to Fridays peace conference. "Progress in respect of the treatment of Basque prisoners would be enormously helpful," he said. But Spanish Interior Minister Juan Ignacio Zoido retorted Wednesday that "they will not obtain a thing for making a declaration they call a dissolution." Many ETA victims or relatives say the separatist group should first and foremost condemn their history of violence and shed light on more than 350 unsolved crimes. "This is not the end of ETA we wanted," Consuelo Ordonez, head of the Covite victims association, said Wednesday at a gathering in San Sebastian, the Basque city most hit by ETA attacks. ETA apologized earlier in April for the harm caused to victims and their relatives. The April 16 letter said that, while ETA is now consigned to history, the drive for Basque independence would continue. “The conflict did not start with ETA and it does not finish with the end of ETA’s journey,” it said. Polls on support for independence vary, but one carried out in November by the university of Deusto showed just 14 percent of people in favor.