Andrew shared his memories of writing for Diana to mark the 20th anniversary of her tragic death.
Speaking on Saturday Night with Miriam on RTÉ One, Andrew told how he was shocked the first time Diana explained her eating disorders and suicide attempts in a series of cassette tape recordings.
Andrew explained: “I got taken to a working man’s cafe in North London. I put on these headphones, he pressed the button on the tape recorder and I was transported into this bizarre parallel universe where Diana was talking about her eating disorders… never heard of them.
Princess Diana biographer Andrew Morton reveals why her death changed Royal Family FOREVER
Royal Weddings throughout history
Fri, February 10, 2017
Tiaras, tulle and fairy tale flair are in full swing at a Royal Wedding
Popperfoto/. Images 1 of 17
Masahito, Prince Hitachi and Hanako Tsugaru (Hanako, Princess Hitachi) pictured together in ceremonial dress in Japan on the day of their wedding, 30th September 1964.
Nobody had ever heard of this woman and I’d been writing about the Royal Family and I thought I knew the Royal Family well. I thought I knew what was going on. Wrong again!
“She was talking about her suicide attempts. These were desperate cries for help. It was like an initial kind of sampler of what she had to say. She was talking about this woman called Camilla.
“Nobody had ever heard of this woman and I’d been writing about the Royal Family and I thought I knew the Royal Family well. I thought I knew what was going on. Wrong again! I was transported into this world and for the next year or so had to try and make sense of it.”
He continued: “She felt absolutely disempowered. She felt like she was living a lie. She realised that the world was living the fairytale or looking at the fairytale of the Prince and Princess living happily ever after, but this was a postmodern fairytale. There was no happy ending.
Charles and Diana: Signs the royal marriage was doomed
Sat, August 12, 2017
Princess Diana and Prince Charles in pictures: Signs the royal marriage was doomed.
. Images 1 of 16
Prince Charles and Princess Diana on their last official trip together, 1992
“For her, she felt that she was a prisoner. She felt like she was being patronised by the men in grey, as she would call them inside the palace.
“Her husband was effectively living with another man’s wife, Camilla Parker Bowles, who was then married.
"She went out into the public and would meet the public, she’d be shaking hands and people would be smiling and cheering. She’d then go back to Kensington Palace… nothing. Silence.”
Prince Charles' relationships
Thu, March 16, 2017
Prince Charles' relationships in pictures, from Lady Tryon to Princess Diana and Camilla Paker-Bowles.
. 1 of 13
Prince Charles' relationships in pictures
The former Royal reporter said that the impact of the book and her death made it easier for Prince William to marry a “commoner” and for Prince Harry to marry whoever he chooses because of how "Prince Charles was constrained by marrying a white Anglo-Saxon virgin”.
Asked why the world is still fascinated 20 years since her death, Andrew said: “It was the same impact as when JFK died. People remember where they were when she died. People watched her transform from a shy young girl to a sleek ambassador.”
Saturday Night with Miriam airs weekly on RTÉ One.