There are many of reasons why Catalonia considers itself different from the rest of Spain and has made repeated calls for independence. Here's a quick run through of some reasons for Catalan independence knocked out without too much thought.
Following the invasion of the Iberian peninsula by the Moors in 711, the Christian 'reconquest' of the north-eastern coastline was begun by the Franks and the Catalan counties were originally a buffer zone between Christian and Muslim territory known as the Marca Hispanica.
Most of this territory became hereditary under Wilfred the Hairy of the House of Barcelona in 897, declared independence from the Franks under Borrell II in 988 and was grouped together Ramon Berenguer IV when he married the Aragonese heiress Petronila in 1137 and became Prince Regent of Aragon.
Their son Alfons became King of Aragon but the Principality of Catalonia retained its laws, charters and political institutions until after the War of the Spanish Succession in 1714 when all of the Crown of Aragon was annexed by force by the Crown of Castile and Spain began to exist as we know it.
Since the mid-19th century increased autonomy and independence have been a permanent source of tension between Catalonia and the Spanish government in Madrid.
Located in the north-east corner of the Iberian Peninsula between the Pyrenees and the Mediterranean, Catalonia has always been a strategic passageway between France and Spain and has not only received cultural influences but has also been invaded from both the north and south.
It has also always been open influence from the sea. The Greeks founded Emporion, the Romans made Tarragona their capital and Barcelona has long been one the Mediterranean's most cosmopolitan cities and an important trading capital for centuries.
In fact, Barcelona is still the capital of a European megaregion that begins at Marseille and stretches down to Valencia and is quite distinct economically from the rest of the Iberian peninsula.
Catalan was one of the first languages to develop out of Vulgar Latin and has almost as much in common with modern French and Italian as it does with modern Spanish.
Its earliest written text, the Homilies d'Organyà, dates from the 11th century but it was a vernacular language long before.
Catalan is not a minority language but rather a stateless one and is spoken as a mother tongue by around 9.5 million people mainly in Catalonia, the Balearic Island, Valencia and the French region of Rousillon.
Not surprisingly, Catalans feel that the 14th most spoken language in the European Union should have the support of its own state.
Obviously speaking the same language is an important unifying factor but there are other cultural differences that distinguish Catalans from other Spaniards.
They have a reputation for being hard-working and mean probably because of their mercantile history and the fact that Catalonia was one of the few places to undergo the industrial revolution.
Catalans are also very group-oriented and have clubs for everything from collecting mushrooms to football supporting. The first peñas or supporters' clubs in Spain were Catalan, their famous human castle-building involves incredible teamwork and even their national Sardana dances has people forming ordered circles whereas passionate flamenco is much more individualistic.
The Spanish national sport of bullfighting was declared illegal by the Catalan Parliament in 2010.
Catalonia suffers a tax deficit with respect to the Spanish state of around 8% of its GDP which in 2010 amounted to €16,000,000,000 of Catalan taxes that were paid to Madrid and not reinvested in Catalonia. This makes Catalonia the most highly taxed region in Europe and its schools, health services, roads and infrastructures are suffering in comparison to supposedly poorer regions of Spain.
Furthermore, many decisions taken by central government have negative effects on the local economy. Here are two examples.
Barcelona Airport despite being Spain's busiest airport some months of the year still has no metro connection, a very poor train service and out of date roads whilst Madrid Barajas has train, metro, new roads and there are plans for a high-speed AVE connection. AENA, the central airport authority, also prioritises intercontinental flights to Madrid meaning there are no direct flights from many destinations to Barcelona, which has a detrimental effect on multinational business in Catalonia.
The Port of Barcelona is one of the busiest in Europe and is so profitable it subsidises other Spanish ports that run at a loss. The Port of Barcelona would be even more successful if it had a freight railway line that could take goods north into Europe because ships from Asia that currently dock in Rotterdam could access the Mediterranean via the Suez Canal. Both Catalonia and the EU have been lobbying for the so-called Mediterranean Corridor, which would also benefit Valencia, Cartagena, Malaga and Algeciras, but central government has blocked the Mediterranean Corridor for years because it doesn't pass through Madrid.
If Catalonia is such an important part of Spain, why doesn't the Vuelta de España cycle race ever come here?
Catalonia is perfect cycling territory with flat plains and Pyrenean mountain ranges and regularly hosts the Tour de France!
I'm currently writing a book on the history of the relations between Catalonia and Spain with a deliberately provocative title
Catalonia Is Not Spain: A Historical Perspective
And you can find out more in general on my blog
Page on barcelonas.com