A royal expert has told of the little-known story of the Duchess of York’s involvement in Princess Diana’s attempt to come to terms with the breakdown of her marriage to the then-Prince Charles.

Princess Diana went through a “revolving door” of “spiritual advisors” on the advice of Sarah Ferguson when she found herself in a loveless marriage to the former Prince Charles, royal author Christopher Andersen has said.

Charles was reportedly instantly smitten when a mutual friend introduced him to his future wife, Queen Camilla, in 971 and the pair initiated a blossoming romance.

Camilla failed to meet the royal requirements for marrying an heir to the throne and went on to marry Andrew Parker Bowles in 1973.

Princess Diana went through a “revolving door” of “spiritual advisors” on the advice of Sarah Ferguson when she found herself in a loveless marriage to the former Prince Charles, royal author Christopher Andersen has said. Picture: Jayne Fincher/Princess Diana Archive/Getty Images

Charles and Camilla had an affair around 1978 or 1979, and they stayed close while the then-Prince began courting Lady Diana Spencer in 1980 and married her in 1981.

Charles and Diana separated in 1992, and Camilla and Andrew Parker Bowles divorced in 1995, with Charles shortly before giving an explosive television interview admitting his relationship with Camilla.

Charles and Diana divorced the following year.

Speaking to Fox News Digital on Wednesday, Mr Andersen claimed: “Over the years, Diana went through a revolving door supply of astrologers, faith healers, numerologists, tarot card readers, clairvoyants, psychics, and ‘spiritual advisors’.”

“Most… told her what she already knew: that her husband was cheating on her with his old flame.”

Royal expert Richard Fitzwilliams told the publication the Duchess of York reportedly introduced Diana to new age practices, and the Princesses’ “reliance” on them soon became “notorious.”

“She was deeply insecure and unhappy herself. Hence, her reliance on healers and the like,” he said.

Fitzwilliams said that, according to English journalist Tina Brown, Diana’s astrologer Felix Lyle instructed her to release the 1992 tell-all memoir Diana: Her True Story.

He said Lyle had connections to Diana’s close friend and “middleman” James Colthurst, who mediated between the Princess and her writer Andrew Morton.

The revelations comes after Vanity Fair reported Diana “also indulged in frequent sessions with alternative medical treatments, including colonic irrigation, reflexology, aromatherapy, acupuncture, and hypnotherapy.”

The outlet quoted a former palace official as telling royal author Sally Bedell Smith that Diana was with “every different sort of person” from the late 1980s to the early 1990s.

The source said the Princess’ turn to the mystical world for guidance was “a cry for help” after she “marched in and out” of marriage with Charles.

Royal expert Richard Fitzwilliams said the Duchess of York reportedly introduced Diana to new age practices, and the Princesses’ “reliance” on them soon became “notorious.” Picture: Julian Parker/UK Press via Getty Images

Diana infamously told the BBC in 1995: “There were three of us in this marriage, so it was a bit crowded.”

The beloved Princess reportedly predicted in writing on several occasions that she would most likely die in a car crash.

Diana died on 31 August 1997 from injuries sustained in a car crash in the Pont de l’Alma tunnel in Paris while her driver, Henri Paul, was fleeing the paparazzi.

The crash also resulted in the deaths of her companion, Dodi Fayed, and Paul, who was also the acting security manager of Hôtel Ritz Paris.

Diana was 36 at the time of her death.