Kristen Stewart's Princess Diana Biopic Has Facts 'All Wrong,' Experts Say

Kristen Stewart's new Princess Diana biopic has got the facts "all wrong right from the beginning" before filming has even begun, experts tell Newsweek.

Spencer will tell the story of the breakdown of Diana's marriage to Prince Charles in 1992, when the royal couple separated after years of unhappiness.

Director Pablo Larraín says he wants to tell a story about "how a woman decides somehow, not to be the queen."

And he indicated it will take place over a key weekend at Sandringham House (the private home of Elizabeth II) on Christmas 1992.

However, royal experts have told Newsweek how she was not at Sandringham that year and it was Charles who chose to split from Diana, not the other way around.

Ingrid Seward, author of The Queen and Di, said: "Of course they got it all wrong right from the beginning because of course that weekend she wasn't at Sandringham.

"That was the only time she didn't go.

"She didn't choose to separate from Charles, that's absolute rubbish.

"She knew that their marriage couldn't continue but the last thing she wanted on God's Earth was a divorce.

"That's also why it went on so long. Charles was desperate for a divorce and it went on and on and on.

"The sad thing about these films is that because Diana is so iconic there really is no room for maneuver.

"You've got to stick to the true story or you'll be beaten before you've begun. Good researchers are hard to find I guess."

The film's announcement triggered a wave of criticism of the casting decision, with Diana fans unhappy with the choice of Kristen Stewart to play their hero.

Peaky Blinders creator Steven Knight may have his work cut out if he intends to craft the fictional retelling into a shape that satisfies fans of the princess.

The film is called Spencer, a reference to the Princess' pre-royal life when she was known as Lady Diana Spencer.

The plot will condense a saga that raged behind palace walls for decades into just three days.

Larrain said: "Diana is such a powerful icon, where millions and millions of people, not just women, but many people around the world felt empathy toward her in her life.

"We decided to get into a story about identity, and around how a woman decides somehow, not to be the queen.

"She's a woman who, in the journey of the movie, decides and realizes that she wants to be the woman she was before she met Charles."

Penny Junor, author of Camilla Parker Bowles biography The Duchess, told Newsweek: "I don't think it was her decision to separate from Charles.

"I wouldn't have said that was how it all played out at all.

"The reason she lashed out so badly and started giving all these interviews to the media was because she was hurt and angry that Charles walked away from her.

"I don't think she was the one who wanted to end the whole thing. That weekend may have been the final straw but she was making life very difficult for him."

Junor said there was a weekend when Princes William and Harry had been due to stay at Sandringham with Prince Charles, but Diana decided at the last minute she would not take them.

The Prince of Wales was furious, having planned the trip months before, and Junor said this may have been a tipping point in the long-running saga.

However, she added: "She was making life very difficult and she was unpredictable in what she would do.

"They were leading very separate lives. It wasn't a surprise. It began to fall apart as they walked down the aisle.

"Seriously, it began to fall apart before they even walked down the aisle.

"He tried very hard to make her happy but it wasn't possible. They were two very poorly suited people."