According to Penny Junor, the author of The Duchess: The Untold Story, the aftermath of Diana going public with her husband's extra marital affair with Camilla was "horrendous."
Royalists will remember how Diana lifted the lid on Charles and Camilla's infidelity in Diana: A True Story - her 1992 collaboration with journalist Andrew Morton.
"[Camilla] was branded a whore, a marriage-wrecker, and adulterer, and Andrew [Parker Bowles] found himself in the curious position of being the wronged husband.
"The harassment intensified," Junor added, describing how Camilla became a prisoner in her own home, while Charles was about to carry-on freely.
"She became the butt of lewd jokes, crude cartoons, lurid headlines; she had disturbing phone calls at all hours of the day and night, received abusive letters, and became a virtual prisoner alone for a lot of the time, in a big house in the country with no security.
"Life became horrendous."
Charles and Camilla eventually went public with their relationship, and in 2005 married.