Pep Guardiola's Barcelona side will rightly go down as one of the greatest to ever play the game.
They won the lot while playing some of the most aesthetically pleasing football ever, spurred on by the likes of Xavi, Andres Iniesta, and of course, Lionel Messi.
The Argentine was initially a brilliant part of a fantastic team but it wasn't long before even a side as great as that Barcelona team was revolving around Messi.
Messi would go on to win the Ballon d'Or in every one of Guardiola's four seasons in charge at Camp Nou, revolutionising the centre-forward role in the process.
Having initially begun as a right-winger who sometimes played centrally, Messi would move inside permanently during the 09/10 season to devastating effect.
A tally of 38 goals in 08/09 became 47 the following year and Messi's first full season as what became to be known as a 'false 9' resulted in 53 goals in 55 games - a new Barcelona record.
It was a tactical masterstroke by Guardiola and one that directly led to Messi being the player he is today - but how did he come up with it?
That has now been revealed by three of Pep's players: Xavi, Thierry Henry, and Messi himself - and it was all down to watching Real Madrid.
"Pep called me a day before El Clasico and he made me come to the Ciutat Esportiva to tell me that we were going to change the position," said Messi on 'Take the ball, pass the ball'.
"He had been watching matches with [his assistant] Tito Vilanova and they had decided to do something new."
"Guardiola changed the system and told Henry to play wide, and Eto'o between the central midfielder and the defence, analysing the movements of Real Madrid," said Xavi.
"Pep had noticed that they never went out to press the number nine of any team, but the numerical superiority we had with Messi as the false nine meant we always had one extra player showing for the ball throughout the game."
"It was something new for Real Madrid," Messi added."They had studied us very well, but we had freedom when I pulled back and when the central defenders had to try and cover Samuel [Eto'o] and Henry.
"Sticking to the players saw Henry score his first goal."
You can see the 6-2 win over Real Madrid they're talking about below:
"It worked: Messi's assist happened in exactly the way that the coach wanted," Henry said.
"Leo delayed in the position and made Real's centre-backs hesitate. I stepped out into space, Samuel moved to the other side and it worked."
And that was it: football history was made - the likes of which we'd never quite seen before.