Princess Diana had a hard time after she joined the royal family.

According to People, the late Princess of Wales' unhappiness with her marriage with Prince Charles triggered her to secretly tell her story through a biography. Princess Diana was reportedly miserable due to Prince Charles' affair with Camilla Parker Bowles.

"It explained Diana's feelings, her sense of isolation, her sense of being a prisoner," royal biographer Andrew Morton said. "Once that leached into the popular imagination and people got to understand who she was as a three-dimensional character, then people responded to her. And you could see that people wanted the Diana monarchy, one that was more approachable, a bit looser. A little bit more empathetic to their own issues and problems."

According to Daily Mail, in Morton's book "Diana: Her True Story," Prince William and Prince Harry's mom detailed her five suicide attempts. "It's hard now to convey the shock, disgust and astonishment that greeted the first instalment," Morton previously said.

Morton was condemned following the publication of the book. His work was also banned by numerous major bookstores and supermarkets.

"But it soon became apparent that the book really was, as it claimed, Diana's own true story," Morton added. "And the Princess quickly began to receive the kind of support that always meant so much to her. Letters came flooding in — many from people who'd suffered from eating disorders themselves."

Paul Burrell, Princess Diana's former royal butler, also revealed that she had a premonition about her death. The Princess of Wales' reportedly suspected Prince Charles of plotting an automobile accident to kill her and marry Camilla.

"Her words were 'these next few months, are the most difficult months of my life. I fear my husband is going to kill me. In an automobile accident. With head injuries. In order that he can remarry,'" Burrell said. "That is spooky. She predicted her own death nine months before she died." 

However, while Morton insisted that the biography is Princess Diana's true story, another author claimed that it was not.  Lady Collin Campbell revealed earlier that Princess Diana hired her to work on her biography prior to Morton. However, she declined because the royal wanted her to write lies.

"She wanted me to effectively tell lies like propaganda. I'm not criticising Andrew Morton — he wrote what she told him," Lady Colin claimed. "He chose to believe all that she said and accepted it undiluted, while I was not prepared to do so."