Clasico of clasicos
Football has many great rivalries. But few can match Real Madrid against Barcelona for historical and political significance or glamour and star appeal.
And on the eve of this clasico of clasicos in Madrid, the unique pressures involved were neatly illustrated by the extraordinary verbal spat between the two coaches.
Barcelona's normally unflappable manager Pep Guardiola finally cracked after his Real Madrid counterpart Jose Mourinho accused him of unfairly criticising referees.
The Bernabeu's press room gasped in amazement as Guardiola, who was still a player when Mourinho worked as an assistant at Barcelona in the 1990s, let rip, swearing twice on live Spanish television, in a highly personal retaliation.
"In the press room he is the ******** chief. He is the ******** man. I try not to play the game off the pitch. He's much better than me at it. I represent an institution that believes this is not the best way to do things."
Great theatre though all this was - and the papers here this morning have devoted pages and pages to the row - there is of course far more to this match.
Cristiano Ronaldo and Lionel Messi will lead a stellar cast of footballing stars at the Bernabeu
First there's the history. Rightly or wrongly, Barcelona supporters see Real Madrid as the establishment club. A view which dates back to the days of the Franco dictatorship when Barcelona became so closely attached with Catalonia's struggle for independence.
That spirit still lives on today, even if the historical barriers are fading with time and seem less significant following Spain's victory in last summer's World Cup - a victory achieved with no less than seven players from the Catalan club.
Then there is the unprecedented series of el clasicos - four matches between the two clubs inside just 18 days. The first League game 10 days ago was a draw but then, last Wednesday, Real ended Barca's recent dominance by winning the final of the Copa Del Rey.
Now the biggest prize of all is at stake - a place in the Champions League final at Wembley next month.
The two squads boast some of the biggest names in world football, fronted by Cristiano Ronaldo for Madrid and Lionel Messi for Barcelona. But there is also Alonso versus Xavi. Mesut Ozil against David Villa.
And the game won't even feature the scorer of Spain's World Cup winning goal, Andres Iniesta, who is injured, or Brazil's Kaka, who is likely to be on the bench for Madrid.
The teams are the result of a transfer arms race which, despite their status as the world's richest clubs, has left them facing severe financial problems.
This might surprise those who hold Barca and Madrid up as the role models for club ownership and management. Both are socios, or mutuals, run by their thousands of members.
No Abramovich or Glazer family here. If the fans don't like the board or the president they can vote to get rid of them. And rather than paying off debts run up to acquire the club the focus is entirely on the development of the club and the team.
Even David Cameron's coalition government has made fan ownership of clubs a policy aim and many supporters groups argue the Spanish system is a better model.
But the democratic nature of these clubs can create political instability and there is concern over debt. Real have net debts of almost £290m while Barcelona are in the red to the tune of £380m.
Both had to raise new funds from banks last year just to meet their spiralling costs and Barcelona's vice president Javier Faus told me in an interview last week that Barcelona were now in a new age of austerity with spending on players limited to £35m a year.
Despite all that they remain hugely valuable clubs - thanks mainly to the fact they, unlike English Premier League teams, are able to sell their television rights individually.
Nothing too democratic about that and there will be plenty of people involved in the English game who will argue that the fairer distribution of media revenues has contributed to the overall global success of the Premier League.
And yet the strength of these two clubs and the success of the national team are still seen as an immense cause for national pride at a time when the Spanish economy is under such intense pressure in the Eurozone crisis.
In between winding up Guardiola, Mourinho described Wednesday's game as a "match beyond this world". So often big games like this fail to match the hype.
But that won't stop Spain coming to a halt tonight or more than 500m people around the world tuning in to see the latest instalment in this unique story.
Real Madrid and Barcelona - the key facts (all 2010 figures):
Value of club (Forbes): $1.4bn
Revenue: 442.3m Euros
Debts: 326m Euros
Profits: 24m Euros
Value of TV deal: 114m Euros a year
Value of club (Forbes): $975m
Revenue: 415.4m Euros
Debts: 430m Euros
Loss: 80m Euros
Value of TV deal: 178m Euros (Real and Barca are worth 50% of the Spanish football TV market)