- Over a fourth of the players on Spain's national football team come from Catalonia. It is also the home of Argentina star Lionel Messi's FC Barcelona.
Overtures of independence have prompted several companies to relocate.
After 2003, Catalonia obtained a new autonomy statute that recognised its sense of nationhood. But Spain's Constitutional Court in 2010 watered down this statute, which sparked a surge in support for Catalan independence.
In January 2016, Carles Puigdemont took over as president and began a push to achieve Catalan independence.
Catalonia, whose leader may declare independence on Tuesday, is one of the most strategic regions of Spain, the eurozone's fourth largest economy.
Bordered by the Mediterranean and the Pyrenees, the region, which has its own distinct language and culture, accounts for 6.3 per cent of Spain's territory, 16 per cent of its population and a fifth of its economic output.
The home of surrealist painter Salvador Dali and architect Antoni Gaudi, its famous Costa Brava, which runs up to the French border, was one of the first stretches of Spanish coast to be developed for mass tourism.
Catalonia is now Spain's most visited region, accounting for 22.5 per cent of the country's international visitors.
Over a fourth of the players on Spain's successful national football team come from Catalonia, which is also the home of Argentina star Lionel Messi's FC Barcelona.
At the same time Catalonia is one of Spain's most indebted regions. Its debt pile stood at 76.7 billion euros ($90 billion) at the end of the first half of 2017, equivalent to 35.4 per cent of its gross domestic product.
The region regularly taps into a credit line run by Spain's central government that provides extra cash to regional governments.
But Catalonia complains that it pays billions of euros more in taxes each year to Madrid than it gets back in services such as schools and roads.
Overtures of independence have prompted several companies to start relocating, including Spain's third-largest lender CaixaBank and energy giant Gas Natural.
The cradle of anarchism in Spain, Catalonia has often had complex ties with the central government in Madrid. General Francisco Franco took away the region's special powers and repressed the use of the Catalan language during his 1939-75 dictatorship.
Catalonia today is one of Spain's most decentralised states. Considered a "historical autonomous region", it has the power to run its education and healthcare systems.