
Catalan colors —
Barcelona's Nou Camp stadium will be transformed into a giant Catalan flag prior to kick off in Sunday's "El Clasico" match against Real Madrid. A total of 98,000 placards will proudly display bands of red and gold.

Messi vs. Ronaldo —
"El Clasico" also brings together the best two players on the planet. Cristiano Ronaldo of Real Madrid, right, has started the season in fine form and scored a hat-trick in Wednesday's European Champions League defeat of Ajax. But it is Barca's Lionel Messi who is revered by many as the finest player in the world. The Argentine has won the FIFA World Player of the Year award in each of the last three seasons.

Mourinho meets Tito —
Real coach Jose Mourinho had a fiery confrontation with then Barcelona assistant coach Tito Vilanova in August 2011. Mourinho poked Vilanova in the eye amid a scramble on the touchline of last year's Super Cup encounter. Vilanova has since gone on to replace Josep Guardiola as Barca coach.

Bitterness and bile —
The rivalry between Real Madrid and Barca is one of the most intense in football, and players who move between the two clubs are rarely forgiven. When Portugal's Luis Figo returned to the Nou Camp after moving to Real in 2000, fans threw numerous objects in his direction -- including the pig's head pictured here.

Calls for independence —
The president of semi-autonomous Catalonia is Artur Mas.He has been accused of using the debt crisis engulfing Spain as a way of garnering more support for the independence movement.

September 11, 1714 —
The Catalan National Day is September 11, commemorating the day in 1714 when the Spain monarchy defeated Catalan troops in the War of the Spain Succession. The day is used to showcase the region's culture and traditions, as well as to campaign for secession from Spain.

Pep rally —
Josep Guardiola, right, gave his support to Europe's victorious Ryder Cup campaign in Illinois last weekend. The former Barca coach has also echoed calls for Catalan secession, declaring on the region's national day: "Here's one more vote for independence."

A history of conflict —
Catalan customs and the region's language were aggressively repressed by general Franco during the Spanish Civil War, which was fought between 1936 and 1939.

Austerity measures —
The Spanish financial crisis has led to a raft of anti-austerity measures. Protests against cuts have been seen on the streets of Madrid, where a minority of protesters have been involved in violent clashes with the police.