Barcelona v Real Madrid, La Liga Venue: Camp Nou, Spain Date: Sunday 29 November Kick-off: 1800 GMT Coverage: Live on Sky Sports One, live text commentary on BBC Sport website with
in Barcelona on Twitter
By Jonathan Stevenson
When Barcelona and Real Madrid meet on Sunday, they do so set against a backdrop of 107 years of classic contests.
But what makes this match-up between Spain's two biggest clubs so compelling it will attract a worldwide audience of one billion people?
BBC Sport asked several former Barca and Real players, including Match of the Day host Gary Lineker, to explain why El Clasico is so special to them and football fans in general.
"I've got a few good memories of playing against Real Madrid. The first time I ever played them at the Camp Nou I somehow managed to get a hat-trick (putting us 2-0 up in the first five minutes) and I also scored the winner in my other two home games against them.
"The atmosphere in these games is incredible. There used to be 120,000 fans - mostly home supporters - in the Barca home games and I got goose bumps, it really was something else. If you scored in the Bernabeu, you could hear a pin drop.
Lineker signed for Barca from Everton for £2.2m after the 1986 World Cup
"I don't think there is anything that quite compares to Barcelona v Real Madrid, it is more than just a football match. It goes back to the oppression of the Catalans under General Franco when the only place they felt they could speak their language was in the stadium.
"The worldwide appeal comes from the fact that it is such an enormous fixture, plus they are two of the greatest clubs in world football. And the biggest stars in the game still always tend to end up at one of these clubs."
"There is one game I remember very well indeed playing for Real against Barcelona.
When talking El Clasico, you are speaking about the greatest football match on Earth
"Johan Cruyff and Johan Neeskens were in the Barca team and we lost 5-0, in our own stadium. You can imagine what that meant, losing 5-0 at home to Barca. People have still not forgotten it to this day.
"On that day we played terribly and nothing worked. Barca were a wonderful team under the control of Cruyff - he was the leader of the side, the master and he made them champions that time.
"Everyone knows what it means to play for Real or Barca against the other. The people demand that you win and as players you do feel under more pressure. It's the ultimate game."
RAFAEL MARTIN VAZQUEZ (Real Madrid, 1983-90 & 92-95)
"I don't have a favourite memory simply because every single one of these games is so special.
"There is one I remember, however, where I played particularly well and we won 3-0, though our manager Luis Molowny was sent off.
"I played a few times against [Barca coach] Pep Guardiola in these games and he has developed a custom of winning already. He understands what Barcelona means and has got them playing in the perfect fashion.
"The matches are huge for the people and in particular for the media. I hope this will be evenly-matched and my heart wants Real to win always, but my head tells me 1-0 to Barcelona."
GHEORGHE HAGI (Real Madrid 1990-92 & Barcelona 1994-96)
"It was a great honour for me to live those derbies and play for these two great football clubs of the world. When speaking about El Clasico, you are talking about the greatest football match on Earth.
Hagi's nickname during his career was 'The Maradona of the Carpathians'
"The first time I played in one, it was for the Spanish Super Cup and I came on for Michel in the final minutes - it was an awesome debut for me! These moments are unforgettable and last a lifetime.
"I spent two years with each club and played with some of the best in the world. I also got to learn from the most important coach I played under: Johan Cruyff.
"This is the game that everyone awaits. In this kind of derby, each player knows he has a unique chance to prove his value. These are the real finals, no matter the rankings or the players' form."
"A game with nearly 100,000 fans is always special and you cannot play enough of those if you love football. They are the best games to play in as a professional.
"The games we won were amazing because the city was filled with pleasure for a month, fans even came to the airport to celebrate.
"A few weeks before the game, the media begins to build up the pressure. The atmosphere in the stadium on matchday is fantastic and the history of Catalonia against Spain also plays a role in Barcelona.
"I always watch if I can and of course I watch as a Cule [Barca fan]! I played for this fantastic club for six years and I still enjoy watching them, especially for the way they play football."
"I have had the pleasure to play in many big matches between fierce rivals, including Feyenoord v Ajax, Rangers v Celtic and lots with Arsenal too.
"But there is not a fixture anywhere that has the global impact of El Clasico, a match that is watched all around the world.
There is not a fixture anywhere that has the global impact of El Clasico
Gio van Bronckhorst
"I was lucky with the results too. We beat them 3-0 and 2-1 at the Bernabeu, which must have hurt and we also won 3-0 at Camp Nou, when I scored. Fond memories, great to look back on when I retire.
"It will be interesting this time to see the clash between Lionel Messi and Cristiano Ronaldo if they are both fit - the two best players in the world. But Barca are favourites as they are a great team; Real are in the process of constructing theirs."
"My best memory of El Clasico is from the 2007-08 season. We became champions the game before and when we took to the field, the Barca players were applauding and honouring us, as tradition dictates in Spain.
Sneijder (right) celebrates Real's 4-1 win over Barcelona in May 2008
"It meant so much to play in this game, you cannot explain it to others. It starts way before kick-off in the media, the people on the streets... it's one of the most special occasions for a footballer.
"It is the biggest worldwide [regular] event in football for me. It is the event of the year and everybody is looking forward to it.
"I'm able to watch, I definitely will do so. Of course my feelings are still for Real, though I don't believe they will win this time."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.