Zinedine Zidane's decision to step down as Real Madrid manager surprised nobody. After all, he'd done it before. Twice. As a player in 2006 and as manager in 2018, he walked away from the club, with no fuss and with no interest in negotiating a payoff. So when the news broke that Zidane had decided to leave again -- on the evening of May 26, while the football world was watching Villarreal beat Manchester United on penalties in the Europa League final -- there was no feeling of shock, though it was surprising to see Carlo Ancelotti return as his replacement.

If you'd been paying attention, you knew that Zidane was never going to settle down and build a dynasty at Real Madrid. He isn't that sort of coach and Real, with its sky-high ambitions, big spending and short-term decision-making, isn't that sort of club.

The signals could not have been much clearer, either. Months and months of hints -- an impending need for change, an insistence on living in the moment, a dismissal of meaningless, long-term contracts -- had left little room for misinterpretation.

It was more of a surprise on Monday when, having turned down the club's offer of a farewell news conference, Zidane made a second decision: to explain himself in an open letter published in the newspaper Diario AS.

In 849 carefully chosen words, Zidane set out why he felt he had no choice but to leave. He wasn't "abandoning ship," he said. He wasn't tired. He was going because the relationship of trust between him, the club and president Florentino Perez had broken.

Zidane is leaving with his conscience clear, sources close to him have told ESPN, convinced that he and his players did everything possible to deliver on the pitch in an extraordinarily challenging 2020-21 season. There is disappointment and regret too, as well as a feeling of unfinished business, that he was unable to see the project he'd envisaged when returning to the club in 2019, less than 12 months after his first exit.

ESPN has spoken to multiple sources close to Zidane and inside Real Madrid, from the board room to the dressing room, to dissect his departure.

How angry is he with Perez and the relentless Madrid media? How close did he come to being fired before he abruptly resigned? Which were the key relationships, and relationship breakdowns, that influenced his decision? And what comes next for coach and club?

"I'm leaving because I feel the club is no longer giving me the trust I need. It isn't offering me the support to build something in the medium to long term... I would have liked my relationship with the club and the president in recent months to have been a little different than that of other coaches." -- Zinedine Zidane, May 31, 2021

Zidane's relationship with Perez is complex. There is genuine gratitude for signing him as a player -- "I can't say no to the president," he said on his return in 2019 to manage a second time -- and the perception of a debt owed. Zidane's family have been based in Madrid ever since he arrived as a player in 2001, with his eldest sons -- midfielder Enzo, goalkeeper Luca -- also passing through the club's academy.

"Spending 20 years at Madrid has been the most beautiful thing that has happened to me," he wrote in Monday's open letter. "I know that I owe it exclusively to Florentino Perez who took a chance on me in 2001, who fought for me when certain people were against it... I will always be grateful to the presi for that. Always."

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Perez valued Zidane's role as a legendary player, a Galactico ("out of this world," in reference to the players Real Madrid always look to sign) icon and a global ambassador for the brand. He also grew to appreciate his knack for winning Champions Leagues: Zidane and Real not only won it in consecutive seasons, but then won it a third straight time. But there were plenty of questions from the start, the most fundamental being: was Zidane actually a good manager? His charismatic aura was undeniable, but surely that wouldn't be enough at the highest level, senior figures at the Bernabeu wondered.

In January 2016, they were willing (or desperate) enough to take a chance. Those doubts were undermined as Zidane's managerial achievements rapidly piled up, reaching their pinnacle with 2017's league and Champions League double, but they never entirely went away. It didn't matter that he'd won more European titles than any other Real Madrid manager before him; this group of players were so experienced and so talented that some executives felt they essentially managed themselves. It didn't really matter who was in charge, as long as they didn't rock the boat.

Zidane was aware of that perception. Even when he left, successors Julen Lopetegui and Santiago Solari failed and Zidane came back again to put out the fire -- something he didn't have to do, risking his Champions League legacy as one of just three coaches in men's soccer history to win three European titles, and as the first ever to do it in three consecutive seasons -- he continued to be taken for granted. He received a "lack of support" from the very top of the club, sources told ESPN, and felt "alone" at key moments. He didn't mind being the only voice speaking up on the club's behalf in news conferences -- "it's part of the job", a source said -- but he didn't enjoy it, either.

It was only when the lack of support Zidane had identified turned into something darker that relationships began to sour. Namely, Zidane felt he was being deliberately undermined via leaks to journalists close to Perez about just how close he was to losing his job; sources told ESPN that this was what had most irritated Zidane, a fact confirmed by his open letter's pointed complaints about "messages intentionally leaked to the media."

The friction between Perez and Zidane felt worthy of a soap opera or prestige drama, and three moments during his second spell in charge stand out. First, a Champions League group stage match with Galatasaray in October 2019, after Madrid had been beaten by Paris Saint-Germain and scrapped to an unconvincing draw with Club Brugge. Out of nowhere, the spectre of a return for Jose Mourinho -- out of a job at the time and for whom Madrid's president still held a torch despite a divisive three-year spell from 2010 to 2013 -- was raised by El Mundo, a newspaper with close links to Perez.

Twice in the 2020-21 season did reports surface in the media of an imminent manager change, and both angered Zidane. First in October 2020, before a must-win Clasico in Barcelona (they did win, 3-1), and again in December when a first-ever Champions League group stage elimination looked likely.

Zidane, for his part, insisted he would not resign under any circumstances. "I've never thought I was untouchable," he said in December. "The club will do what it has to do, as always."

"I'll never be Madrid's [Sir Alex] Ferguson, that's for sure," he chuckled later that month, referring to Manchester United's iconic manager after Zidane and Real Madrid racked up three job-saving wins against Sevilla, Borussia Monchengladbach and Atletico Madrid in the span of a week. "I don't know how long I'll be here, so I don't even think about it."

Throughout the 2020-21 season, a crisis was never far away. A perfect storm in Jan. 2021 saw Madrid lose to Athletic Bilbao in the Spanish Supercopa, and be knocked out of the Copa del Rey by third-tier Alcoyano, before Zidane tested positive for COVID-19. He had to self-isolate, which he later described as "being locked in a cage for two weeks." Zidane had time to reflect and, crucially, read more reports of how close he was to losing his job after a loss to Levante on Jan. 30 left Real 10 points off league leaders Atletico.

His first news conference back on Feb. 5 was incendiary, at least by Zidane's standards. The usually taciturn manager had some premeditated things to get off his chest.

"We deserve to be here until the end of the season," he snapped. "After that, a lot of things will happen. But as a team we're not going to give up... Are you serious, asking me if I'll resign? Everyday people say I'm out. Last year we won the league. We did, Real Madrid. We have the right to fight for our title this year at least.

"Next year they'll have to do things, change, maybe. But this year, we have the right to fight. Let us fight. This squad won the league last year, not 10 years ago. A bit of respect for that... Say it to my face: I want you to go. We want you to go. But you have to say it."

Zidane's rant had been aimed at Perez and the press, not the players, but the team responded, going on a 19-game unbeaten run. Yet senior figures at the club told ESPN that Zidane "couldn't complain" about anything, as they saw it. He had been given near "free reign" over two-and-a-half years, they said. Rumours about his future didn't go away, but that was down to Zidane's own refusal to commit, not leaks from higher up.

"I don't look beyond what I'm doing now. I don't plan ahead at all," he said in March after fielding further questions about his future. "You could sign here for 10 years and you're out tomorrow."

By early May, Zidane's mind was more or less made up. He planned to leave, however the season turned out. "What I can say is I'll make it easy for the club, always," he let slip on May 8. A week later, he veered off script. "I'm sorry, I know what I say is boring, but it's true, I don't know what will happen," he began. "You talk about me leaving in 2006 and as coach (in 2018)," he said. "You might think I walk away from responsibility or leave when things get complicated, but no, never.

"What I do is give everything, to the end, and then the moment comes to change, not just for me, for the good of the players too... I don't leave because it's easy. No, there are moments when you have to stay, and others when you have to go."

Twelve days after that, he was gone.

Zidane's big-game record as manager was extraordinary, something that was true from the very start. He won his first game in charge. He won his first Champions League game. He won his first Clasico. And he never looked back.

But he also dislikes much of what goes along with being a top-level modern manager: the media noise, the short-termism, the posturing. But he loves being on the training ground with his players. Hardly a session went by at Valdebebas without the 48-year-old coach getting involved in the introductory rondos, or passing moves, that form part of the warm-up.

He has said before that in his head, he's still a player, and for that reason, Zidane always prioritised squad harmony above everything else. "Everyone is important," he would repeat endlessly. The atmosphere had to be right.

That meant his return as coach in 2019 came with strings attached, as Zidane expected a series of conditions to be met. Near the top of that list was what one source termed an "immediate" departure for Gareth Bale. The relationship between the two had already reached its crisis point around the 2018 Champions League final. Zidane dropped Bale in Kiev, only to see him come on and score twice to win the trophy, almost in spite of his coach. Zidane left days later, and Bale stayed. When Zidane returned, there was no prospect of reconciliation.

A speedy resolution to the Bale problem wasn't the only demand that went unmet. Zidane wanted the club to prioritise the signing of a powerful box-to-box player that he felt necessary to complete the team's midfield.

"He had Marcos Llorente and didn't want him," a source inside the club told ESPN. The coach would have preferred Paul Pogba, with his staff pointing to data they said proved Pogba would out-perform Llorente "in top-level games." But Pogba was deemed too expensive by the club, and never arrived. Nor did anyone else of a similar profile. Zidane had to use Federico Valverde, a promising player but at an earlier stage of his career, in the role.

There were frustrations from the club's side, too. A long-standing complaint, endlessly voiced by senior club sources, was Zidane's alleged mismanagement and lack of faith in expensive young stars, as he preferred the players he could rely on.

His relationship with captain Sergio Ramos, for example, was one of mutual respect. The pair had briefly played together, a teenage Ramos joining Madrid in 2005 in time for Zidane's final season. Karim Benzema -- the most important forward in the squad after the 2018 departure of Cristiano Ronaldo -- idolised Zidane, describing him as "like an older brother." Zidane called Benzema the best French striker of all time.

The midfield trio of Casemiro, Modric and Toni Kroos loved Zidane too. And he loved them. When the coach's job was saved by the 2-0 Madrid derby win in Dec. 2020, Zidane couldn't contain himself. Kroos, Modric and Benzema were "f---ing great," he gushed.

Zidane's loyalty was, in the club's view, a weakness. He persevered with Isco and Marcelo -- outstanding in 2016 and 2017 -- long after their on-field performances and attitudes had drastically deteriorated. He also backed goalkeeper Keylor Navas when Florentino Perez wanted to sign Kepa Arrizabalaga from Athletic Bilbao in Jan. 2018, forcing the club to ditch a deal that was just waiting to be signed off.

When it came to players such as Vinicius Junior, Zidane's staff called for "patience". That wasn't acceptable to senior figures at the club, who were exasperated by the lack of involvement for a number of expensive youngsters. These prospects had to become "realities" and soon, club sources said, as they doubted Zidane was the man for the job.

How many young players had truly improved under him? How many had left, permanently or on loan, only to prove their worth elsewhere? The friction over this issue was a steady, background hum of discontent throughout Zidane's two spells in charge. The club cited his handling of forward Luka Jovic, a player Zidane had specifically asked for and quickly gave up on. Midfielder Martin Odegaard was another case in point, recalled early from his successful Real Sociedad loan at Zidane's insistence, only to become frustrated at his limited opportunities and leave again, joining Arsenal for the 2020-21 season.

When the going got tough, Zidane turned to his tried and trusted veterans, time and time again, and hoped that their legs could take it. Over 60 injuries -- counting those that forced players to miss games -- in 2020-21 suggested that what had previously been his greatest strength, making the most of his squad, had failed him.

After they exited the Champions League with defeat to Chelsea in the semifinals, there was, if anything, surprisingly little criticism of Zidane and the team. The consensus was that an exhausted squad's limits had been reached, as much as the limits of Zidane's own tactical acumen up against Thomas Tuchel and the eventual winners.

Each Real Madrid manager tends to be a reaction to the last. A tough guy is often followed by a soft touch, and vice versa. There is a yearning from club president Perez for mano dura -- "a strong hand" -- and for someone to take back the power from the dressing room, putting the players in their place. That explains the appeal of Mourinho after all these years. It also explains the longstanding links to Antonio Conte, vetoed by the dressing room in Oct. 2018, when Sergio Ramos famously said that "respect is earned, not imposed."

The return of Carlo Ancelotti this week contradicts all that.

The chief complaint against the Italian -- whom everybody likes -- when he was sacked in 2015 was that his sessions weren't demanding enough, that there was a lack of rigor and discipline, the players instead allowed to rule the roost. Yet Ancelotti's rehiring is only really possible because he left on good terms. Zidane did that the first time, but he won't be back again. His open letter was rich with intent: it was an explanation of why he walked, an exercise in self-justification for his actions and, most importantly, it was a call for cultural change at Real Madrid. It was also a burning of bridges, as Perez does not tolerate such public dissent.

Zidane has always been an unconventional football figure. It was true as a player -- who moves the way he did? -- and it's been true since. He is not subject to the same incentives or restraints as his managerial contemporaries, though that's not to suggest that Zidane doesn't care. He does, passionately. He isn't defined by the job, nor beholden to it. He doesn't need it. He just loves staying close to football, working alongside top players.

"I appreciate it every day," he said this month. "The best thing is being with the players. I love watching them play. I get emotional."

His options to operate at a similar level -- coaching the best of the best -- are now limited and only two jobs really make sense: Juventus, who have just opted for Max Allegri, and the France national team. It remains to be seen if, or when, he'll try again.