Last and Present Season

The rivalry intensified in 2011 where due to the final of the Copa Del Rey and the meeting of the two in the UEFA Champions League, Barcelona and Real Madrid were scheduled to meet each other four times in 18 days. Several accusations of unsportsmanlike behaviour from both teams and a war of words erupted throughout the fixtures which included four red cards. Spain coach Vicente Del Bosque stated that he was "concerned" that due to the rising hatred between the two clubs, that this could cause friction in the national side.

Real and Barca, slugged it out an unprecedented five times last season in three different competitions. Barcelona came out on top in the league and Champions League semi-final while Real won the King's Cup in a series of matches notable more for the increasingly acrimonious atmosphere between the clubs than for the quality of their football.

Super Cup holders Barca have eclipsed their arch-rivals over the last three years by winning two European Cups and a treble of league titles, which means this showdown is important more as a psychological indicator of the clubs' strengths.

Real coach Jose Mourinho ran Barca close in his first campaign in Spain and has often stated that his teams usually do better in his second year in charge.

They have won all seven pre-season warm-up matches with ease, though only Portuguese defender Fabio Coentrao has had the chance to make an impression out of the new arrivals.

Turkish midfielders Hamit Altintop and Nuri Sahin have been sidelined with injuries. Mourinho also has a doubt over Sergio Ramos, who pulled out of Spain's squad for the midweek friendly against Italy with a recurrence of a back problem.

On the positive side, France striker Karim Benzema has been in fine form scoring eight goals in pre-season to date.

Barca boss Pep Guardiola, who has three wins and one draw from his four visits to the Bernabeu as coach, has yet to give his only new recruit so far his debut. Chile forward Alexis Sanchez, along with Argentine Lionel Messi, have only just returned to training after July's Copa America tournament.

Many Barca fans will be hoping the drawn out transfer saga surrounding Arsenal captain Cesc Fabregas will have been concluded by the weekend and that the club's former youth team player will at least be in attendance in the stands.

Barca's pre-season form has been patchy and they often take a while to get into their stride in a season.

Controversies

A rivalry doesn't go without controversies. The El Clasico was from the very beginning were surrounded by controversies. The most popular among them is the "Di Stéfano transfer", Di Stéfano had impressed both Barcelona and Real Madrid whilst playing for Club Deportivo Los Millonarios in Bogota, during a players' strike in his native Argentina. Both Madrid and Barcelona attempted to sign him and, due to confusion that emerged from di Stéfano moving to Millonarios from River Plate following the strike, both clubs claimed to own his registration. After intervention from FIFA representative Muñoz Calero it was decided that both Barcelona and Real Madrid had to share the player in alternate seasons. Barcelona's Franco-imposed President backed down after a few appearances, as Barcelona's side claimed, but Real say Barcelona's decision was voluntary and di Stefano moved definitively to Madrid.

Di Stéfano became integral in the subsequent success achieved by Madrid, scoring twice in his first game against Barcelona. With him, Madrid won the initial five European Champions Cup competitions. The 1960s saw the rivalry reach the European stage when they met twice at the European Cup, Real Madrid winning in 1960 and FC Barcelona winning in 1961.

Recently

The two teams met again in the UEFA Champions League semi-final in 2002, with Real Madrid winning 0-2 in Barcelona and a 1-1 draw in Madrid. The match, dubbed by Spanish media as the Match of the Century, was watched by more than 500 million people. In the Clásico held on November 2005, Barcelona played away in Madrid, winning 3-0. The star of the Barcelona team was Ronaldinho, who became the second Barcelona player after Diego Maradona to receive a standing ovation from Real Madrid fans.

The rivalry has been strengthened throughout time by the internal transfer of players between the clubs. Barcelona players who have later played for Real Madrid includeBernd Schuster, who switched in 1988, Michael Laudrup went to Real Madrid on a free transfer in 1994, but the most notorious was former vice-captain Luís Figo's switch in 2000. Players transferring from Real Madrid to Barcelona are less frequent, the most recent being Luis Enrique, who went to Barcelona in 1996 where he went on to captain the Blaugrana, and since 2008, coaches the reserve team.

FANS

A 2007 survey by the Centro de Investigaciones Sociológicas determined that Real Madrid was the team with the largest following in Spain. Thirty-two percent of the Spanish population supported Real Madrid, while twenty-five percent supported Barcelona. In third place came Valencia CF, who were supported by five percent. Barcelona in turn is more popular in Europe than Madrid. According to a survey made by the German research agency Sport+Markt in 2010, Barcelona has approximately 57.8 million fans around Europe, while Real Madrid has 31.3 million fans. Globally, Real Madrid is the most popular football club in the world according to a study performed by Harvard University in 2007, with over 228 million supporters worldwide.
PS- I'm a fan of RM.

The Begining

The present teams and coaches.

As usual politics and it's extra long roots creep in everywhere, even these mighty clubs have long been politically motivated. As early as 1930's the two clubs started to be in tune with two opposing political traditions, FCB for Catalan pride and tradition and RM for centralizing tendencies of Madrid.
During the Franco dictatorship, most citizens of Barcelona were in strong opposition to the fascist-like régime. Phil Ball, the author of Morbo: The Story of Spanish Football, calls the El Clásico "a re-enactment of the Spanish Civil War". A similar analogy was made by American author Robert Coover, which described the 1977 match between the "archrivals" Barcelona FC and Real Club Deportivo Español as "more like a reenactment of the Spanish Civil War than a mere athletic event."
The first match between them was held in 1902 but the first match between them whose score i could find is the match in 1929 February 17, in which RM won 2-1.
And from then on The Fight was on.

Introducción

Not a spelling mistake but it's introduction in Spanish because we're talking about THE El Clasico here.

To begin with El Clasico is the name given yo any match between Real Madrid and FC Barcelona. To begginers they are two football clubs, rumored to be the best (one of the richest, most successful and influential) in the world (which is 1st and which next is still a matter of controversy).

El Clasico means The Classic in English. The name is worth it because it is one of the highest viewed match every year.