Sunday's controversial election in Catalonia has been styled as a vote on secession. Here we look at the history of the independence struggle since the early 20th century

General Francisco Franco mounts a military coup. It fails in Catalonia, but succeeds elsewhere, sparking the Spanish Civil War which last for nearly three years.

A victorious Franco executes Lluis Companys, president of the Catalan government, by firing squad at Montjuic Castle in Barcelona. Over the following 35 years, Catalan identity and language - considered subversive by the regime - is severely repressed, and all political institutions abolished.

Franco dies. A period of transition ensues, and in 1977 democratic elections are held and the Generalitat re-established. The next decades see a Catalan revival.

The Statute of Autonomy is approved by the Catalan parliament and by the Spanish parliament a year later.

Spain’s constitutional court waters down the powers of autonomy contained in the Statute and strips the word “nation” from the text, stirring anger in Catalonia.

Artur Mas, the Catalan president. Photo: David Ramos/Getty Images Artur Mas, the conservative Catalan president, asks for negotiations on a new fiscal pact with Spain, reflecting feelings among many Catalans that the powerhouse region gives more to Spain than it gets back. Madrid refuses negotiations. A major independence demonstration sees 1.5 million take to the streets of Barcelona, according to police estimates.

Mr Mas asks Spanish prime minister Mariano Rajoy to discuss a referendum. Madrid declines.

With parliamentary backing, Mr Mas convenes a consultation vote for November 9 of that year. Madrid appeals to the constitutional court, which declares the process unconstitutional.

The Catalan government pushes ahead with a non-binding consultation vote despite warnings from Madrid. Eighty-one per cent of voters come out in favour of an independent Catalan state, though turnout is relatively low at around 42 per cent.