The phoney war is over. Now the actual war starts, and for Real Madrid there are few battles more bitter, few duels as destructive. CSKA Moscow and Apoel have been dispatched, as were Dinamo Zagreb, Lyon and Ajax. Madrid have reached the semi-final without facing a team from Spain, Germany, Italy or England. Now, a fearful and familiar rival awaits and at a familiar stage too. Real Madrid v Bayern Munich feels like a proper European Cup semi-final. Timeless.

They have met four times in European Cup semi-finals. Yet even the "friendlies" have ended badly. There have been walk-offs, stand-offs and plenty of sending-offs.

This may well be the only genuine, cross-border rivalry in Europe. Sure, there have been isolated moments – Chelsea supporters will probably never forgive Barcelona, for a start – and, sure, the Spanish dislike the Italians. But Manchester United still seek enemies in England, while Internazionale and Milan still seek theirs in the same city. The enemy within is the real enemy. Madrid-Bayern is different. Barcelona apart, no one gets the Bernabéu really roaring like the "teutonic" team.

Between them they have won 13 European Cups. Historically, they are their country's richest, most successful and best-supported sides and they know it. They are also their countries' most despised. Dominating and domineering, two behemoths snarling at each other. Two giants that, for all their similarities, could hardly imagine a club more different. When they confront each other they really confront each other – and they have confronted each other often.

They first met in the European Cup semi-final in 1976. A Bayern team boasting Müller, Maier, Rummenigge, Hoeness and Beckenbauer went on to win their third consecutive European Cup; Madrid went on to a five-year ban after a fan – for ever known as El loco del Bernabéu – ran on and attacked the linesman and Müller. The ban was later reduced to three matches played away, but the seed was sown.

Four years later, they met in a pre-season friendly and Bayern won 9-1, prompting the Madrid manager Vujadin Boskov to shrug: "I'd rather lose by nine once than by one nine times." If that sounds like perspective, think again. The following summer, Bayern were invited to Madrid's pre-season Trofeo Bernabéu. Klaus Augenthaler was sent off for making offensive gestures towards the fans. His team-mates walked off the pitch in protest; the game was abandoned.

More semi-finals arrived. The Quinta del Buitre may be the second-best team in Real Madrid's history but the thorn in their side was a big one: they never won the European Cup or even made the final. They made three semi-finals. Milan did them most damage, PSV Eindhoven too. But Bayern helped stick the knife in. In 1988, Madrid defeated Bayern in the quarter-finals; the previous year, 1987, they had lost to them in the semi-final. After a penalty was awarded to the Germans, Juanito lost his head and stamped on Lothar Matthäus's. Repentant, he later apologised in person, but he got a five-year ban. It was the last European game he played.

Bad memories for Madrid, but there were good ones too: the last two times they won the European Cup, they beat Bayern in the semi-finals. An omen?

Bayern could hardly believe they had been beaten: frankly they were the better team. Between 1999 and 2004, the two sides faced each other in three out of four seasons. In 1999-2000, they played four times. Bayern won three and lost one of them, beating Madrid 4-2 and 4-1 in the group. Yet it was Madrid who reached the final and won it. Just as Madrid won the European Cup in 1998, ending a 32-year wait. Their manager? The current Bayern coach Jupp Heynckes. He was sacked immediately.

During the galácticos era, the tension soared. Both sides saw provocation in every act. When Claudio Pizarro joked, "We're going to put five past those clowns!", Spain's best-selling newspaper, Marca, flew into a fit of righteous indignation. Oliver Kahn became a comic bad guy. Bayern were portrayed as snarling animals, anti-footballers, lacking respect. In Germany, Madrid were posers, equally disrespectful. Hoeness dismissed Madrid as a "circus".

"They were performing flicks and back-heels, showboating, not playing football. A complete lack of respect," recalled Kahn in 2002. "It wound us up, so we really went for them – and they didn't like it." Bayern won 2-1. When Kahn then added: "No one can get two past me in the second leg," Marca responded: "One's enough, smarty pants!" Anyway, Madrid did get two.

As if all that were not enough, now there is Arjen Robben, the former Madrid player forced out and with a point to prove, and the Mourinho factor. "Just because you wear cashmere sweaters, doesn't make you a gentleman," bristled the Bayern grandee Beckenbauer. "He is rude and loutish." Between Madrid and Bayern, the feeling is mutual.