Princess Diana reportedly gave up on her marriage to Prince Charles when he had an accident in 1990.

Prince Charles

Prince Charles

The late Princess of Wales decided it was the "last straw" when her then-husband refused to let her visit him in hospital but allowed his now-wife Camilla Parker Bowles to visit.

In his memoir, Diana's former bodyguard Ken Wharfe writes: "Diana confessed to me ... with absolute determination, that this was the last straw. Her compassion was wasted on her husband ... what the prince didn't want, the public did."

Meanwhile, Wharfe previously claimed Prince Charles never knew how to "deal" with Princess Diana.

He said previously: "The Prince didn't know how to deal with her popularity. Diana made desperate attempts to try to put that right. They could have been the biggest double act in the world, but after that confrontation with Camilla and Charles she felt there was no return.

"Diana really tried. I remember once after an engagement we arrived back at Kensington Palace as the Prince was getting into his car. He waved and said, 'Did you have a good day?' She said, "Yes, it was fantastic, where are you going now?' 'Going to do my churches in the City.'

"'Oh that'll be nice. You like all of that. Well, do you want me to come with you?'. [Charles replied] 'No, they'll only be interested in you. In essence there was nowhere for her to go. Diana was desperate, and desperate people often do desperate things."