01 of 09Police face off with demonstrators outside a polling station, in Barcelona, Spain, 1 October 2017
02 of 09A boy waves a flag as people celebrate Catalonia's parliamentary vote to declare independence
03 of 09Catalan leader Lluis Companys (centre) was jailed for declaring independence. He was eventually released but when Francisco Franco took power he had Companys executed in1940.
04 of 09Demonstrators holding a pro-independence rally in Barcelona.
05 of 09Spanish women celebrating Josep Tarradellas’s return to Barcelona two years after Franco’s death. Tarradellas was the exiled president of the nationalist Catalonian government.
06 of 09A controversial statue of Francesc Cambó, a conservative politician who had championed Catalan independence, being unveiled. It was sculpted by artist Victor Ochea.
07 of 09Though the push for Catalan independence was largely non-violent, not all movements in the region were peaceful. Here three members of Basque separatist group eta are calling for a definitive end to 50 years of armed struggle, which had cost the lives of at least 850 people.
08 of 09The then president of Catalonia, Artur Mas, casting his vote on 9 November in Barcelona. This symbolic poll on secession was held after the Constitutional Court suspended its plans for an official independence referendum.
09 of 09Demonstrators waving pro-independence Catalan flags during a rally as part of the celebrations of the National Day of Catalonia in Barcelona.
As the issue of Catalan sovereignty remains a point of crisis in Spain, we chart the timeline of that chaotic referendum and what it might mean for other regions seeking to go it alone.