Everybody could see it happening, piece by piece, but nobody fully believed it, until now.
Xavi Hernandez has resurrected Barcelona; Barca are back.
Their 4-0 destruction of Real Madrid at a broken Santiago Bernabeu will go down with other historic results, like the 6-2 in 2009 or the 5-0 in 2010, but perhaps it will prove most similar to the Blaugrana's 2-1 win in the Spanish capital in 2004.
Xavi scored that night for Barcelona, who did not win the league, but did help Valencia overtake Real Madrid to claim La Lig. More importantly for the Catalans, it kick-started a new era.
After years of suffering at the hands of their eternal rivals, Barca made that night a turning point. Great success followed, but even before the trophies began flooding in, supporters understood how big it was.
Around four thousands fans headed to the airport to greet the team on their return from Madrid, sensing a profound change was coming.
This victory, humiliating for the league leaders but not likely to be damaging to their title hopes given their nine-point advantage on second-place Sevilla, feels similar.Getty Images
Barcelona had lost their last five Clasicos, four in La Liga and the Spanish Super Cup clash in January, their worst run in the fixture since the 1960s.
That defeat in Saudi Arabia felt significant, a turning point, one which was greeted as such by president Joan Laporta, who praised the team effusively, despite losing.
It was understandable, given the improvement was obvious, albeit still frustrating to lose to your most bitter rivals. Frenkie de Jong, who was stellar at the Bernabeu on Sunday, noted that Barcelona should never be content to lose a Clasico.
It spoke not only to his high standards, but those of Xavi and his team, constantly seeking to improve performances and correct mistakes.
The remarkable thing is how quickly Xavi has breathed life into a Barcelona that managed just two goals in their six Champions League group-stage games and were relegated to the Europa League, while also languishing ninth in the table.
There have been numerous steps forward since Xavi returned ‘home’, with big wins over Atletico Madrid, Napoli and Valencia particular highlights, as well as a general acknowledgement that the team are improving with every game.
The players are increasingly capable of following the system Xavi has set up and the automated moves he wants them to be able to pull off in their sleep.
No longer do Barcelona look blocked and incapable of mentally taking on a game of this size.
Just as they came from behind against Galatasaray in a fiery Istanbul atmosphere on Thursday, they strolled at the Bernabeu, turning it into their garden.
From the dynamic attacking of Ousmane Dembele and Pierre-Emerick Aubameyang, who combined brilliantly for the first goal, to Ferran Torres wandering through Madrid’s shellshocked defence at will, Barca dominated.
They won by four but eight would not have been unfair or unrealistic. This was a ‘baño’ - a bath - for the hosts, and players who looked washed up for Barcelona months ago, the veterans like Jordi Alba, Sergio Busquets and Gerard Pique, were elite again, from start to finish.
Xavi is playing a game that suits them, bringing back Pep Guardiola-style football, and suddenly Barca’s elder statesmen look rejuvenated.
Even with the team comfortably dominating the game, Xavi screamed from the touchline, demanding perfection.
He got the decision right to start Ronald Araujo at right-back, with the centre-back handling the electric Vinicius Junior well and netting at the other end to double Barcelona’s lead.
Torres’ movement continues to delight, and even though the Spain international's finishing has been variable, he brilliantly whipped home the third from Aubameyang’s backheel, before the Gabon international netted the fourth with an exquisite chipped finish.
On top of Xavi’s work, sporting director Mateu Alemany got his calls right in January to bring in the dynamic striking duo, along with Dani Alves and Adama Traore.
Madrid were without Karim Benzema, but even if the Frenchman was fit, the gap between the two sides looked seismic. Ancelotti had changed to a diamond midfield, which may have thrown his players, but Xavi’s Barcelona look capable of beating whoever is put in front of them.
He became the first Barcelona coach to win his first Clasico in La Liga by four goals since Helenio Herrera in 1959, and four felt fitting, given Xavi famously provided four assists in the aforementioned 6-2 win over Madrid in 2009.
Xavi dominated Madrid as a player in that game, and now he has done it again from the technical area. And he’s only just beginning.
This match, though, was a chance for Barcelona to send a message to their rivals. But instead of dropping it through the letter box, they knocked down the door.
“We are back,” wrote Gerard Pique on Twitter, spelling it out minutes after the game ended. Who can disagree?