Britney Spears said she was used. Kevin Federline says she needs help

Britney Spears stared at herself in a mirror, grinning as she grabbed an electric clipper.

Chunks of her long, iconic locks fell to the floor of the Southern California salon. Paparazzi cameras outside documented every second of the now-infamous night in 2007, later following her with her new buzzcut to get a tattoo.

The star said she did it because she felt cornered and humiliated by the paparazzi, who had chased her from the house of her estranged husband, Kevin Federline.

In the midst of an acrimonious and widely publicised custody battle for their two young boys, the Princess of Pop said she acted out in defiance and wanted to give the press "some material". She called it an impulsive decision - one that to her, served as a public rebuke to a world she felt held her to untenable standards.

To her, it was a "desperate move by a desperate person".

But to her estranged husband, it was a wake-up call to "just how far things had spiralled out of control".

Decades later, those moments and the others that went on to define the pop star and her very public unravelling are back in the limelight - but what exactly happened and why depends on who is doing the retelling.

After Spears shared her outlook in her 2023 memoir, The Woman In Me, Federline is now speaking out and sharing his take on their years together in a book released this week, titled You Thought You Knew.

Like Spears, Federline's book details their intimate and chaotic relationship, the mental anguish they both suffered and provides an inside glimpse at the conservatorship battle that dictated much of Spears' life and career. It provides a side-by-side look, a he-said, she-said dissection of their lives.

The Grammy Award winner, 43, has already denounced her ex's memoir, writing on social media that Federline's revelations have been "extremely hurtful and exhausting".

But the dancer-turned-reality TV star says he's releasing You Thought You Knew after years of hesitation because he does not want his children growing up "feeling like they have to explain who their father is".

Federline responds to the stories and accusations that Spears tells in her 2023 tome, in which she describes being financially and emotionally controlled by those closest to her. He contradicts her account at times, levying fresh accusations.

Despite both memoirs offering vastly different accounts at times, both have a similar aim in reframing the public narrative thrust upon them by illuminating the episodes that led to Spears' conservatorship battle, as well as the nationwide movement that freed the pop star in 2021.

Britney Spears' father, left, was appointed by a court to be in charge of her finances and career

Did the conservatorship help or hurt?

In her book, Spears condemned the court-ordered conservatorship, also known as a guardianship, which she was under from 2008-2021. During that time, her father, Jamie Spears, was in control of her finances, career and many aspects of her personal life.

She says that if she was just left to live her life, she would have worked it out.

"Thirteen years went by with me feeling like a shadow of myself. I think back now on my father and his associates having control over my body and my money for that long and it makes me feel sick," she wrote.

But, she added, she resolved to go along with the protracted arrangement "for the sake of my sons," even though "being in it was really hard".

After the conservatorship ended, her father Jamie Spears said it had been "necessary" to protect her, but it was time for her to have control back.

In his recounting, Federline has a different take. Even when the marriage tanked, it wasn't easy for him to "watch her spiral", he writes.

Federline supported the arrangement, arguing that it provided "some semblance of normalcy" for their two boys together. After her psychiatric hold, Federline says he immediately filed for sole custody, but that set into motion a slew of issues that exacerbated Spears' relationship with their children.

His ex, he writes "saw the events in her life through a prism that painted her as the victim, the misunderstood one, the person wronged by everyone around her.

"But from where I stood, she needed help. Whether that was rehab or therapy, I couldn't say for sure," he writes, noting that she was in no state to manage her own affairs and needed some form of oversight or "protective layer".

He adds that he came to find out that there was a lot he didn't know about the conservatorship, and he did not push for answers because part of him "doesn't want to know".

Did the Free Britney movement get it 'wrong'?

Spears has credited the viral Free Britney movement with helping her find the courage to challenge and eventually escape her conservatorship.

"The fact that my friends and my fans sensed what was happening and did all that for me, that's a debt I can never repay," she wrote, thanking them for standing up for her when she couldn't stand up for herself.

But Federline says the movement "got it wrong" and those who are part of it now need to put the same effort into a "Save Britney movement". He shares ominous concerns about how the pop star is currently "racing toward something irreversible" and "getting close to the 11th hour".

The pressure from the Free Britney movement, he alleges, led the judge on her conservatorship case "to ignore the professional reports and cave to public opinion".

"But none of that truly mattered in the end. If Britney believed she was being held against her will, and everything else she's shared since, then that trauma is real for her. And you can't ignore that," he says.

Spears has continued to make headlines with strange and sometimes concerning posts on Instagram. Their boys are grown up but, according to Federline, they have haven't seen their mother much, and they don't really want to. Federline has four additional children, along with the two with Spears.

Federline says he has lost faith that things will ever fully turn around for his ex-wife.

"I still hope that Britney can find peace. Whatever her future holds, I hope it's one where she can finally take control of her own life, on her own terms. This whole saga, twenty years of it, was built on denial. Britney never reached the first step of recovery: admitting there was a problem."

Spears has said she felt constantly cornered by paparazzi cameras that followed and dissected her life

A ghost in their marriage

Spears has laid blame on many people who were once close to her, including two of her exes, Federline and former NSYNC frontman Justin Timberlake.

She accuses both of ruining her ability to "trust people again".

In his own memoir, Federline says he was making a career for himself as a professional dancer who worked with Michael Jackson and NSYNC when he crossed paths with Spears.

The couple had met before, when Federline was dancing on a tour for Spears' opening act.

Federline, for his part, is self-aware, writing that he knows people viewed the Fresno, California, native as "this dude jumped out of his trailer and into Britney's mansion".

But even the day before their wedding, there was a shadow over the relationship, he says.

Federline contends in his book that when he and Spears got together in their early 20s, she had never really moved on from her ex-boyfriend Timberlake, detailing that they had a lot of "unfinished business" and that "it lingered, like a ghost in the background of our relationship".

In her memoir, Spears recounted the pitfalls of her relationship with Timberlake, including him asking her to have an abortion and the public embarrassment that befell her after he accused her of cheating - further heightened when he cast a Spears lookalike in his music video for Cry Me a River.

Britney Spears and Justin Timberlake were the globe's most famous celebrity couple.

Their relationship, which lasted from 1999 to 2002, has also been dissected over the years and has come with a public apology from Timberlake, after several documentaries about Spears recast her as a victim in her conservatorship.

Federline says that "there was always something there with Justin that she couldn't let go of". He says Spears even called Timberlake the night before their wedding to get closure.

"Now, looking back... I realise it was deeper than that. She never really got over him," he writes.

Re-igniting an old feud and an army of fans

Federline's memoir has raised the ire of Spears, and her vocal army of online supporters.

James Miller, an activist and Free Britney proponent, says the book will not help the singer.

"Britney does struggle with mental health problems, that's pretty obvious," he told the BBC. "Exploiting her right now really isn't the best time. I don't think there's any alarm to sound."

Fans protested outside the courthouse as Spears fought to be freed from her conservatorship

From breaking out on The Mickey Mouse Club as a child star to dancing with a snake around her shoulders at the MTV Music Video Awards, Spears has lived her whole adult life in the spotlight.

S Mark Young, a professor at the University of Southern California and author of The Mirror Effect: How Celebrity Narcissism is Seducing America, says Federline's book is unlikely to change people's minds about her.

"I think after this coming week, the book will die. Most people who follow Britney will not be moved," he says.

Some have wondered why Federline, 47, has chosen to speak out now.

"No one heals when a book like this is written," Mr Young says.

Mr Miller, and many online, have noted that now that their sons are both over 18, Federline would no longer be receiving a $40,000-per-month payment from the singer to support them.

Federline denies having an ulterior motive beyond wanting to finally share his side of this infamous saga.

Federline says he worked hard to not just live off of Spears' money, such as DJing in Vegas in 2018

In the memoir, Federline says the book was his best chance at sharing his side of the story.

For decades, the media, Spears and her family have mostly told Federline's story, largely leaning into his "bad boy" persona and making him the butt of many late-night jokes.

"This is about finally telling my story," he writes in his book. "My version. In my words. Because everybody else has done it for me. The media. The blogs. The exes. The strangers. The jokes. The headlines. They all had something to say about me. And I stayed quiet."

He denies that he ever "was just coasting off her money" and insists he has always been "out there hustling, grinding, investing - working to build a solid foundation for myself and my kids".

This opportunity was a way for him to finally share his side after decades of stories, gossip, rumours and accusations - which he says he avoided responding to in hopes of giving his family and children "some kind of normal life".

"But silence didn't bring peace," he writes. "It left me choking on the words I never said."