Around 175,000 people joined hands in a human chain stretching 125 miles last Sunday across the Basque country in the Spanish state.
It was the biggest mobilisation in decades for the right to hold an independence vote.
The Gure Esku Dago (It’s in our hands) group organised the event.
“We have proved that we want to decide the political future of this country,” said spokesperson Angel Oiarbide.
The movement in Catalonia—and the repression it has faced—has encouraged the Basque movement to come onto the streets.
There is also anger at a recent court case in which eight young Basque people were given long jail sentences for assaulting police officers.
The court said “radicalisation, animosity and intolerance” towards security forces caused the assault.
The Basque armed separatist organisation, ETA, announced it was disbanding in May.