Diana secretly contributed to the biography by recording her stream-of-consciousness-style thoughts.
It's no surprise that Princess Diana's story has been front and center in season 5 of The Crown. The Netflix royal drama has finally reached the '90s, which was dominated by the late Princess of Wales, whether it be for her fashion or the very public breakdown of her marriage to Prince Charles.
The second episode of season 5, titled, "The System," focuses on another story of Diana's, her biography, and the secret tapes she recorded for author Andrew Morton.
In 1992, Morton's book -- Diana: Her True Story -- was the tell-all to end all tell-alls. Upon its release, Morton claimed that he did not interview Diana for the book, but it was later discovered that she recorded a series of stream-of-consciousness recordings with her friend, James Colthurst, that Morton used to craft the book. Morton was asked to consult on the relevant episodes of The Crown, and recently shared with Good Morning America just how impressed he was by the show's accuracy.
"It left me breathless and it took me back all those years. I don't say this very often, but I was shaken," he says of actress Elizabeth Debicki's portrayal of Diana and the show's recreation of the historic events.
"The screenwriters asked me all kinds of questions like, 'What was the color of the wallpaper in my daughter's bedroom?' Because that's where I had an office for a time," he notes.
Morton's biography featured shocking revelations including Diana's multiple suicide attempts, memorably one where she threw herself down a flight of stairs while pregnant with Prince William, her struggles with eating disorders, and the difficult life she faced within the royal family.
"What I didn't realize at the time was her sense of isolation, her sense of despair inside the System," Morton tells GMA.
Before the recorded tapes were ever released, Diana gave her subtle endorsement of the book by going to meet with her old friend, Caroline Bartholomew, who contributed to the book. Diana was purposefully photographed leaving Caroline's home and giving her a hug after the book's release, solidifying her support of the book.
The biography was an instant bestseller, with a television film with the same title made in 1993 featuring actress Serena Scott Thomas playing the role of Diana.
After Diana's death in 1997, Morton released a new edition of the book, retitling it, Princess Diana: Her True Story In Her Words, once again making a nod to her contribution to the book.
In 2004, NBC aired an hour-and-a-half-long special documentary titled Princess Diana: The Secret Tapes, featuring the audio recordings Diana had made for Morton's biography.
The full documentary is available to watch on YouTube.
Morton has gone on to pen more memorable biographies including Meghan: A Hollywood Princess about the Duchess of Sussex Meghan Markle and Monica's Story about Monica Lewinsky. His next biography, The Queen: Her Life, will focus on the late Queen Elizabeth II.