Prince Charles only married Princess Diana because his father sent him a threatening letter telling him to propose because her ‘reputation was on the line’.
He thought that Philip, who communicated with his son by letter and not by speaking to him, was issuing him an order that said: ‘You’ve got to get engaged’.
According to family friend Pamela Hicks, Charles ‘wasn’t in love, he wasn’t ready….psychologically he assumed his father bullied him, so he read it as a bullying letter’.
The extraordinary claim is in a new biography of Charles by New York Times bestselling author and royal family biographer Sally Bedell Smith.
She chronicles the life of the heir to the throne in a riveting, Prince Charles: The Passions and Paradoxes of an Improbable Life, which will be released on April 4.
She details how Charles and Diana were a terrible match from the start of their ill-fated union in July 1981.
Charles only married Diana, a former kindergarten teacher, because his real love Camilla Shand, now his second wife, Camilla, Duchess of Cornwall, was not virginal enough for royal custom.
During their rows at Kensington Palace Diana used to taunt Charles that he would ‘never be king’, knowing it caused him deep consternation.
Bedell Smith claims that Diana used to hit Charles over the head when he knelt down to pray by their bed at night - and continue berating him during his prayers.
The book portrays Charles, 68, in an unflattering light and writes that he and his staff ‘dealt with Diana’s bewildering and often infuriating behaviour by placating her, trying to distract her and, ultimately, out of frustration, abandoning her’.
The book makes it clear that the real love of Charles’ life is Camilla, 69, whom he first met in 1972.
Camilla was an upper class girl and he daughter of a British Army officer with a low, husky voice.
Lady Annabel Goldsmith called her ‘an intensely warm maternal laughing creature, with enormous sex appeal’.
Charles adored how Camilla ‘always listened’ to him, Bedell Smith writes, and in her he ‘found the warmth that he yearned for’.
But it wasn’t to be because Charles was not ready to settle down with her at the age of 24.
More importantly family friend Patricia Mountbatten said there were ‘obvious problems’ with Camilla.
The conventions of the time called for a princess to be virginal, or at least appear so, and Camilla ‘had a history’, as Mountbatten put it, ‘and you didn’t want a past that hung about’.
Even though Camilla married another man, Andrew Parker Bowles, her affair with Charles would continue for much of his marriage to Diana.
By the time Charles reached the age of 30, the pressure to get married was intense and after a series of flings Diana entered his life.
According to Bedell Smith she was in the wrong place at the wrong time - and she married the wrong man.
In 1980 Charles’ relationship with Diana, the daughter of John Spencer, Viscount Althorp, had become ‘clandestine’.
With no proposal from Charles the royal family felt her ‘honor had been impugned' and that she was 'besieged' by the press who camped outside her front door.
At the time Diana, who was just 19 and lacked the confidence that came so easily to Camilla, confessed to a neighbour she felt 'miserable'.
In January 1981 Diana arrived for a three day visit to Sandringham, the royal family estate in Norfolk, England, and Bedell Smith says it was a 'tense month all round'.
At this point Philip decided to weigh in with his letter in which Bedell Smith writes that he 'told his son that Diana's reputation was on the line because of all the speculation in the press'.
Philip said 'Charles should either propose to her or release her. In either event, he should make a decision shortly'.
Bedell Smith writes: ‘Perhaps Charles could have understood the nuances of his father’s message more clearly if he and Philip had talked it through.
‘But written communications were the regrettable norm for father and son. Charles chose to interpret the letter as coercive and accusatory’.
Another factor was the restrictions imposed on Charles’ choice of a bride.
According to Bedell Smith: ‘In 1980 - more than a decade after the sexual revolution had started - he was hemmed in by the royal custom of marrying a virgin, or at least a woman who seemed virginal.
‘He was forced, in effect, to rob the cradle….the 12 year gap between Charles and Diana was essentially unbridgeable.
‘They had no intellectual connections, few mutual friends, no interests in common and none of the shared life experiences he would have had with a contemporary.
‘Although Camilla had the same limited upper-class education she was on Charles wavelength - absorbed as he was by hunting and other country pursuits, at home in the same social circle - in a way Diana could never be’.
The marriage would be marked from the start by jealousy from Diana about Camilla which fueled her bulimia, self harm and paranoia.
Diana felt the royal family were cold and did not welcome her. Bedell Smith says her relationship with The Queen was ‘correct’ but the Monarch’s ‘self-containment unnerved’ Diana.
Diana's suspicion over Camilla soon spilled over into a poisonous obsession the played to her insecurities, Bedell Smith writes.
The book says: ‘One of the saddest aspects Diana’s short and tragic life was the failure of those around her - friends and family alike - to convince her to get a proper diagnosis and treat her extreme symptoms of mental instability….bulimia, self mutilation, depression, acute anxiety, paranoia.
‘She was tormented by feelings of emptiness and detachment, she feared abandonment, she had difficulty sustaining relationships and she kept those closest to her on tenterhooks with her sudden moods swings, explosive rages and long sulks’.
Diana banished most of Charles’ friends from their lives because she was convinced they were conspiring against her, the book says.
She even got rid of Charles’ Labrador, which she made him keep with an aide.
One time Diana heard Charles murmuring to Camilla affectionately on the phone and on another occasion she found a bracelet with the initials ‘GF’ engraved on it, or ‘Girl Friday’, his nickname for her.
According to Bedell Smith Diana was ‘high functioning’ meaning she was ‘capable of putting on a great show in public which made her dark upheavals more unfathomable to those around her’.
The book says that ‘Charles ‘lacked the knowledge or the temperament to genuinely help her.
He tried to find her a therapist but she required ‘constant support’ and he could not give it to her.
Bedell Smith makes this point by portraying Charles as comically particular and stuck in his ways.
The first time Diana saw his dressing room she was stunned how a valet would lay a shirt out on the bed.
If Charles didn’t like it he would ring a bell so the valet came back and got him another shirt.
According to Bedell Smith, Diana asked why Charles didn’t just change it himself rather than the valet. Charles said: ‘Because he’s paid to do it’.
Typical of Charles’ behavior was how he had the same breakfast every day, a handful of specially mixed wheat germ and cereal grains, honey and preserves on a silver tray, plus some cut fruit and tea.
He never ate lunch and preferred afternoon tea with a slice of Welsh fruit cake. Charles’ favorite dinner was a soft boiled egg and salad.
At home the royal butlers mixed Charles a dry martini or two but if he was on the road his royal protection officer carried the ingredients for the martini in a special case.
Charles would also bring his own chef to cook his meals, even if he was attending an event at a friend’s house. And he bought his own salt which was placed next to him in a small silver and vermeil bowl.
According to Bedell Smith Charles and Diana stopped having sex in 1984 after just three years together and began sleeping in separate rooms.
By the end of 1986 they were living separate lives - and Diana was having an affair with her riding instructor, Captain James Hewitt of the Life Guards in the Household Cavalry.
According to royal biographer Jonathan Dimbleby there is no question she also had an affair with Barry Mannakee, a royal protection officer.
Another of her lovers was said to be Will Carling, the former England rugby captain.
In her famous interview with the BBC program Panorama in November 1995 Diana admitted sleeping with Hewitt.
Speaking about Camilla, she told interviewer Martin Bashir: ‘There were three of us in this marriage, so it was a bit crowded’.
Bedell Smith writes that Charles had ‘thought he could grow to love Diana, just as the arranged marriage of his grandmother and King George VI later grew into love’.
But six years after his marriage, in anguish he wrote to a friend: ‘How could I have got it all so wrong?’
They were too unalike and on his wedding eve, he wept. He was still in love with Camilla, a woman who was vivacious, irreverent, indifferent to fashion and style, unassuming and affectionate.