After writing books on both Prince Charles and Princess Diana, the royal biographer, Penny Junor, is writing a book about Prince William. Apparently, when she had visited Wales to meet Charles and Diana, the princess was carrying Prince William.

According to Junor, Diana suffered lots of tragedies in her childhood and hence tried passing on the tension to her sons as well. Diana's mother had left her to be with her lover after she suffered a violent marriage and the death of a child.

"It meant that Diana didn't know how to be a mother. She lost hers at an early age. And Diana had a serious mental illness. Bulimia is not just about trying to get slim. It's all about control: the one thing you can control is your diet. Diana's early life was chaos. She was dishonest [with others] because that is part of the disease," Junor told the Daily Mail.

Junor reveals many secrets of Diana. According to the biographer, the princess became unhappy after her marriage to Charles and hence was having an affair with her bodyguard which led Charles into a state of stress.

"He grew profoundly depressed when his marriage wasn't working. The man I interviewed in 1987 was already deeply unhappy. He wanted that marriage to work, he wanted what his friends had - a happy family. He wanted someone to support him, to help him, to be with him and boost his confidence, and he felt personally responsible for the failure of the marriage," Junor revealed. But unfortunately as soon as Charles proposed, Diana seemed to have lost her happiness.

"Until he asked her to marry him, Diana was the most delightful, bouncy, funny, charming girl who seemed to love everything about him. He thought: "I might not be in love with her just yet, but I easily could, because she is adorable and everyone adores her. On paper, she was perfect. She was the daughter of an Earl, her father had been an equerry and lived on the Sandringham estate, and the Spencers and the Royal Family had intermingled over centuries. But the minute they got engaged, she turned into a stranger - he was committed and thought the problems were him and the stress of the engagement," Junor said.

The book, that has already received lots of criticism, will be released on Prince William's 30th birthday.

Princess Diana in red.Reuters
Princess Diana in black.Reuters
Princess DianaReuters
Princess Diana is shown wearing a Victor Edelstein gown as she dances at a November 9, 1985 White House dinner with actor John Travolta. The ink-blue Edelstein gown sold for $222,500 during an auction at Christie's auction house in New York June 25, the highest price paid for any one of the 79 gowns worn by the Princess and auctioned to raise funds for AIDS and cancer charities in Britain and the United States.REUTERS/Handout Old