Basques from Spain and France on Saturday formally launched a new pro-independence party, Sortu, born from the ashes of Batasuna which was outlawed for links to armed separatists ETA.
About 300 delegates from the Basque regions of Spain and France elected leaders for the left-wing party at a congress in the northern Spanish city of Pamplona.
They chose former Batasuna member Hasier Arraiz Barbadillo, 39, as party leader and as secretary general Arnaldo Otegi, who is in jail for trying to resurrect Batasuna after it was banned in 2003.
Barbadillo told the gathering: "Full freedom is our aim" for the Basque Country, called Euskal Herria in the Basque language, which spans parts of northern Spain and southern France.
"In Euskal Herria and wherever it is present, Sortu will be the mouthpiece for your struggle," he told delegates.
The left-wing pro-independence movement has gained political weight in Spain over recent years as ETA has declined with many of its leaders getting arrested.
In his absence, Otegi addressed the congress in a letter in which he called on members to "fight in a new political phase" for the independence movement.
ETA is blamed for 829 killings in a four-decade campaign of bombings and shootings for an independent Basque homeland. It is classed as a terrorist group by the European Union and the United States.
It announced a "definitive end" to its armed activity in October 2011 but has not formally disarmed or disbanded as the Spanish and French governments demand.
Otegi called the Basque independence movement "a political conflict that is still unresolved because the Spanish and French states continue to deny the nationhood of Euskal Herria and its right to self-determination."
Spanish authorities banned Sortu in 2011 because of its links to Batasuna, which was considered the political arm of ETA. The Constitutional Court legalised Sortu in 2012.