The demand by large sections of Catalan society for independence from Spain is today the biggest challenge to the territorial, social and political order that emerged in this country after the end of the military dictatorship of General Francisco Franco. Although this demand has a long history traceable back to 1714, the present context has a differential element. Now the Catalan sovereignist demand and the response of the Spanish state can no longer be negotiated within the traditional boundaries of the nation-state, but must take into account a supranational unity –the European Union. What possibilities and limits does this represent for the aspirations of an independent Catalonia, or for the reconsideration of the Spanish territorial model? How does the Catalan case relate to that of Scotland in the face of Brexit? What role does it play in the re-emergence of the Spanish far right? What expectations and tensions does it raise for the newly established progressive coalition government in Spain?