El Clásico could be found at its most dramatic during Jose Mourinho's spell at Real Madrid.
Amidst a story of personal rejection, and harbouring a football philosophy that was anathema to his new club's arch-rivals, the Portuguese boss set out to undermine what looked to be an invincible Barcelona.
Pep Guardiola and the late Tito Vilanova both had infamous run-ins with Mourinho.
The media did not seem to take to him either, or at least he never encountered the same adoration as he had enjoyed in England and Italy.
However, in 2012, he finally achieved what he had been appointed for. Real were champions of Spain for the first time in four years.
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History may not remember Mourinho's Madrid as anywhere near in the same bracket as Guardiola's Barcelona.
Over the past decade, in fact, regardless of the manager, it's clear which club has come out on top in domestic football - the Champions League is another matter, of course.
That's thanks in large part to Leo Messi, who was at his very peak while Mourinho was in La Liga.
The Argentine has never really slowed down, but the difference was the rest of his teammates - and indeed his manager - were closer to his alien level back then.
Given the thankless task of trying to outdo a team boasting arguably the Greatest of All Time, Mourinho admits that managing Real at the height of Messi's powers did at least make him a better coach.
"I always say that I owe so much to my players, as to those who have not been my players and have created problems for me," he said, per Marca.
"For example, Messi never played on my team but I played against him and he made me a better coach for having to prepare matches, for having to organize my team.
"When I say Messi I also say all the great players I have played against."
If anything, Mourinho's presence in the Bernabeu hot seat only inspired Barcelona all the more.
After the manner in which his Inter Milan had knocked the Blaugrana out of Europe in the semi-finals the previous season, there was a definite sense of revenge about their 5-0 trouncing of Real in 2010.
That was Mourinho's first experience of El Clasico, though the irony is Messi was not on the scoresheet on that occasion.
Xavi, Pedro, David Villa (2) and Jeffren all put his side to the sword, Sergio Ramos' red card compounding their misery.
Yet it is Messi who continues to define so many of his opponents' careers, for better or for worse.News Now - Sport News