It has been revealed how Diana hit out when Charles left her alone and 'nearly knocked a flunky flying' when she found a bracelet for Camilla. Photo / Getty
An explosive biography of Camilla - to mark her 70th birthday next month - lifts the lid on her affair with Prince Charles.
Mail royal author Penny Junor, who talked to Camilla's friends and family, revealed how Charles wept the night before he married Diana.
Today, she tells how the marriage drove him to the brink of a breakdown...
Camilla Parker Bowles approved, and so did her husband Andrew. The 19- year-old girl who was dating the Prince of Wales struck them both as very sweet and funny.
Whenever he brought Lady Diana Spencer to their home - Bolehyde in the village of Allington, Wiltshire - she helped around the house and was noticeably good with their children.
Camilla definitely liked her; and at first, Diana liked Camilla and appreciated her friendship - a friendship that was genuine.
Of all Charles's friends, only three raised question marks about his happy-go-lucky and unaffected new girlfriend, and they weren't thanked for their concerns.
Nicholas Soames, later to become a Tory MP, thought the pair had too little in common and was worried about the intellectual gap between them. Norton Romsey, the grandson of Earl Mountbatten, agreed.
His wife, Penny Romsey, was also worried that Diana was more in love with the concept than the man. After all, she'd once been heard to say: "If I am lucky enough to be the Princess of Wales..."
It was as if Diana were auditioning for a part, rather than truly understanding what she'd be taking on. And she seemed to enjoy being photographed all the time, while protesting at the intrusiveness of the Press.
But what made Soames and the Romseys particularly suspicious was the way she'd gone after Charles with single-minded purpose. She'd set her sights on him, flirting and flattering and bending over backwards to be everything that he wanted her to be.
Norton had spoken to the Prince several times about his reservations, on each occasion more bluntly. But each time, he'd had his head bitten off.
The Queen offered no opinion, though the Queen Mother was enthusiastic. She liked Diana, and was pleased that she was the granddaughter of her old friend Ruth, Lady Fermoy.
As for Lady Fermoy herself, she knew very well that her granddaughter was more complicated than she seemed, and there's no question that she should have alerted Charles. But she was socially ambitious for her family, so she said nothing.
Years later, in 1993 - a month before she died - Lady Fermoy apologised to both the Queen and Charles for failing to warn them. She'd known, she admitted, that Diana had been "a dishonest and difficult girl".
Whether this would have made a difference is open to question - because the opinion Charles trusted most when it came to choosing his bride was that of Camilla, his best friend and lover.
But, still, he was anxious. As he told a friend at the time: "It is just a matter of taking an unusual plunge into some rather unknown circumstances that inevitably disturbs me, but I expect it will be the right thing in the end."
He liked Diana, but he'd started seeing her only six months before and they scarcely knew each other. On the other hand, she seemed so perfect in so many ways that he couldn't risk losing her.
He'd always believed that love could grow out of friendship; what really mattered was that his bride should know what she was taking on. And with all her family links to the Royal Family, surely - at least in theory - Diana had to be the right woman.
'Immature and naïve, Diana lived in a fantasy world of Barbara Cartland novels'
What Charles had yet to discover was that she was very badly educated, naïve and - by her own admission - immature. She lived in a romantic fantasy world of women's magazines and Barbara Cartland novels, which could not have been more divorced from reality.
She'd never been in love before, either. If she had, she would have known that their courtship, which involved minimal touching and was constantly conducted in the presence of Charles's friends, was not the way most people build a relationship.
As soon as her engagement to Charles was made public, Diana moved into Clarence House to stay with the Queen Mother for a few days, then to a suite of rooms at Buckingham Palace.
On her bed at Clarence House, she'd found a letter from Mrs Parker Bowles, asking her out to lunch. It was a friendly gesture and Camilla remembered the lunch as being just that; Diana was very excited and gleefully showed off the ring.
Naturally, they didn't discuss Camilla's affair with Charles. The physical side of their relationship had ended once he'd proposed to Diana, though he'd hoped that their long-standing friendship might continue.
Camilla knew how painful it was to have an unfaithful husband - as we revealed in Saturday's Mail, her own husband's serial adultery was a source of bitter pain for her.
She would never have wanted to inflict that on Diana or anyone else. She wasn't scheming. But over time Diana had come to see that lunch as part of a conspiracy.
Years later, she told Andrew Morton, the author of Diana: Her True Story, that the encounter had been "very tricky indeed".
With hindsight, she'd convinced herself that Camilla was playing a Machiavellian game when she asked whether Diana planned to hunt when she was staying at Highgrove.
In Diana's mind, Charles's lover - who was a member of the same Beaufort Hunt - was trying to gauge whether the coast would be clear for the affair to continue.
It was all nonsense. The Prince, however, must take some blame for Diana's paranoia, because he hadn't handled things well. Instead of explaining to her at the outset that Camilla was an old girlfriend, he'd presented her as nothing more than a friend.
It simply hadn't occurred to him that Diana needed to know the truth before someone else told her. Or that she might feel foolish, embarrassed or humiliated to have chatted openly about her feelings for him to a woman she then found had once been a lover.
Once the engagement was announced, however, he did come clean, admitting that Camilla had been one of his most intimate friends. But he reassured Diana that, from now on, there would be no other women in his life. And he meant it.
A close friend of Charles says of his marriage to Diana: "He made a huge mistake. You can sympathise with Diana - oh God, yes. Put that way, he was the architect of the disaster... also he wouldn't have had the sensitivity.
"He's very interested in objective things, but not subjective, so he couldn't have understood the complexities of her feelings.
"He reads essays, history, no novels. He loves Shakespeare and that teaches you something, but I think if you are in a position like him, novels would be a great antidote to your isolation."
In the months leading to her wedding, Diana changed radically. She was no longer the bouncy girl Camilla had first met; she suddenly became moody, wilful and unpredictable.
There were terrifying rages, temper tantrums, hysterical tears for no apparent reason, and her moods changed in a flash.
She became jealous - obsessing about Camilla and turning against people she'd appeared to like, convinced they were out to get her, undermine her or spy on her.
It also became abundantly clear that she hated being alone, and resented the Prince working. She couldn't understand why his work had to take precedence over them being together - even though, as a working member of the Royal Family, Charles's life was mapped out six months in advance.
Astonishingly, Diana was jealous of anyone he spent time with, including his mother. She thought his private conversations and correspondence with the Queen were about her.
Charles was as bewildered as everyone else, and put Diana's behaviour down to nerves and stress, which he assumed would disappear once the wedding was behind them. No one realised then that the changes in her personality were symptoms of her bulimia - the secret illness that had now taken her over.
It's impossible to know exactly what it was that triggered Diana's eating disorder, but her sudden ascent to fame and the stress of being watched, followed, photographed and written about would have been a lot for even the most confident 19-year-old to handle.
This had been accompanied by a massive change in lifestyle - and maybe, too, the fear that the man she was going to marry didn't love her as much as he'd loved his previous girlfriend.
Camilla did what she could. As soon as she realised Diana had a problem with her, she kept her distance from Charles. Whenever she was invited to a social gathering at which he might be present, she stayed away, saying: "Wales will be there."
But he did speak to her often on the telephone - sometimes, according to Diana, within earshot of her, which resulted in terrible rows. And when Camilla was ill with meningitis, he asked his right-hand man Michael Colborne to send her flowers.
Diana knew about the flowers - because she knew about everything that went on in Colborne's office - and she wasn't happy.
When it came to choosing her attendants for the wedding, she objected to Charles's suggestion that Camilla's son Tom - his godchild - be one of her page boys. There was a big scene about Tom, and the Prince backed down.
On July 29, 1981, Charles and Diana were married in St Paul's Cathedral. He wasn't convinced that he was doing the right thing, but there was no way out.
So, bolstered by the hope that things would be different once they were married, he put a brave face on it. Diana had also had qualms.
She'd told her sisters the day before that she couldn't go through with it, now that she knew Charles was having a last lunch with Camilla in order to give her the bracelet.
On the day before the wedding her sisters told her: "Bad luck, Duch (her family nickname); your face is on the tea-towels and it's too late to chicken out."
The Parker Bowles attended the wedding - Camilla, dressed in a grey suit and matching pillbox hat with a veil, was seated next to her sister and her son Tom. Andrew was on duty, commanding the Household Cavalry escort for the newlyweds.
As Charles walked down the aisle, he looked over at Camilla with a "slightly plaintive, sad look" on his face. Their wonderful affair was over, and reality was kicking in.
It was for Camilla, too. Her husband was now allegedly in the midst of an affair with Charlotte Hambro, the sister of Charles's friend Nicholas Soames. That August, Camilla was unusually subdued on the annual family holiday in Ischia, Italy.
The disastrous honeymoon full of warning signs
Meanwhile, Charles and Diana were on their honeymoon. Starting with a few days at Broadlands -the Hampshire family seat of Charles's late great-uncle, Earl Mountbatten - it included a two-week cruise around the Mediterranean and Aegean, followed by several weeks at Balmoral.
The whole thing was a disaster, serving only to demonstrate how very little they had in common.
The Prince had envisaged a wonderful holiday in the sun, swimming, reading, painting and writing thank-you letters. So he'd taken along his watercolours, some canvases and a pile of books by the Afrikaner mystic and writer Laurens van der Post, which he'd hoped he and Diana might share and then discuss in the evenings.
Diana, however, was no great reader. She hated his wretched books and was offended that he might prefer to bury his head in one of them rather than sit and talk to her.
She resented him sitting for hours at his easel, too, and they had many blazing rows. One day, when Charles was painting on the veranda deck of Britannia, he went off to look at something for half an hour. He came back to find she'd destroyed his painting and all his materials.
Diana didn't tell Andrew Morton about that, but she did tell him about two other incidents.
On one occasion, she and Charles had been consulting their diaries when a photograph of Camilla fell out of his. Another time, when they were in formal dress for dinner, she noticed the Prince was wearing a pair of gold cufflinks engraved with interwoven Cs.
"He said: 'Yes, so what's wrong? They're a present from a friend.' And, boy, did we have a row. Jealousy, total jealousy..."
It's hard to believe that anyone as intelligent and well-read as the Prince of Wales could be so stupid - so utterly incapable of imagining what a new wife might conclude if her husband carried a photograph of his old girlfriend in his diary.
Or, indeed, if he decided to wear cufflinks bearing her initials, when he must have had dozens of others to choose from.
But Charles was already way out of his depth. He had no idea how to treat a wife, let alone one who was secretly making herself sick several times a day.
He didn't even know how to look after himself, since he'd hardly ever had to. Apart from his time at boarding school and university, he'd been waited on hand and foot for 32 years. He didn't even dress himself.
And while he was famous for shouting at underlings, no one - with the possible exception of his father - had ever shouted at him before. He had no idea how to respond.
Balmoral battles as Princess raged, binged, vomited and obsessed over Camilla
In Scotland they held a photo-call by the River Dee and, looking gloriously coquettish, the new Princess of Wales said she could 'thoroughly recommend' married life. "It's a marvellous life and Balmoral is one of the best places in the world."
Nothing could have been farther from the truth. She hated it. She hated the countryside, hated his family's passion for horses and dogs, hated the rain that poured down remorselessly; and she felt that her husband was avoiding intimate contact.
She was raging, bingeing, vomiting and obsessing about Camilla - and getting no meaningful reassurance from Charles.
And he was being driven away and ever deeper into himself.
They didn't stay in the main house, but they had dinner with the rest of the Royal Family several times a week, and as usual his friends were invited - although not the Parker Bowles - so there was very little chance for the sort of intimacy she'd hoped for on honeymoon.
And Britannia, with 21 naval officers, a crew of 256 men, a valet, a private secretary and an equerry all along for the ride, hadn't been much better.
Charles couldn't see it, or if he could, he wasn't prepared to change his ways. Balmoral was his favourite place on earth and he had thought Diana liked it too. She had said she did, but she'd said a lot of things she didn't mean during their months of courtship.
He retreated to the hills and spent his days on solitary walks, or with his paints or books or fishing rod. He left it to others to deal with Diana.
He rang Michael Colborne and asked him to catch a train to Aberdeen. "I will be out stalking that day," the Prince informed him, "but I will see you before I go and I'd like you to spend the day with the Princess."
When he arrived at Craigowan Lodge, the small house where the newlyweds were staying, the Prince thanked him for coming and with no explanation left the house, accompanied by Norton Romsey.
There followed the most shocking, distressing and draining day of Michael's life.
For six solid hours, with no distraction beyond a plate of sandwiches at lunchtime, he sat there while Diana cried, paced around the room, kicked the furniture, ranted about everyone and everything to do with the place that she hated so much, and then fell into brooding silence before starting all over again. At five past four she suddenly said: "I'm going upstairs," and left the room.
Later that evening Michael was due to drive with the Prince to Aberdeen to board the royal train - Charles had an engagement the next day.
Michael was waiting in the dark by the car outside the front door and could hear a monumental row taking place inside.
Moments later the door flew open. The Prince came out shouting, 'Michael!' and threw something at him. It was Diana's wedding ring, which by some miracle he caught before it disappeared into the gravel.
She had lost so much weight that it no longer fitted and she wanted him to take it back to London to be made smaller. The Prince was in a filthy mood and laid into Michael, in front of his detective and valet, all the way to Aberdeen, calling him every name under the sun for a catalogue of failings.
Michael refused to engage and once on board the train ordered himself a treble gin and tonic. Before he could take the first sip, the Prince bellowed his name from down the corridor.
The Prince offered him a drink. 'Tonight, Michael,' he said, 'you displayed the best traditions of the silent service. You didn't say a word. I hear you've had a rough day.' 'Yes,' said Michael. 'I've had an awful day.'
For the next five hours or more they talked about Diana and all that had happened since the wedding. Charles was mystified and despondent. He didn't know what had gone wrong or how he was going to cope.
Five years passed. By 1986, Camilla Parker Bowles seemed to have achieved the dream she'd had since the age of 17 - to become an upper-class country wife, with children and horses and an enjoyable social life.
At her Georgian house in the Cotswolds, she was ensconced in a life of humdrum domesticity - with chickens, horses and a vegetable garden.
Her affair with Prince Charles was becoming a distant memory, and she'd had very little contact with him since the royal wedding in 1981.
Every year, he'd sent Christmas cards addressed to both Camilla and her husband Andrew. And once, he'd actually phoned to tell her that Diana was pregnant.
But the only glimpses Charles ever caught of Camilla were fleeting ones, when they both attended the oldest and biggest fox hunt in England. He no longer came to the Beaufort Hunt meet, where everyone gathered before setting off, and always rode up front with the huntsman, ahead of the rest of the field.
Perhaps seeing Camilla from afar made him fondly remember all their happy times together, and compare them with the nightmare he was experiencing with Diana. But so far as any contact between them went, that was the extent of it.
He was now aged 38, and his close friends were beginning to fear for his mental health. The joy and the sparkle had gone out of him. He was no longer fun to be with - he'd become serious, moody, morose and difficult.
"Frequently I feel nowadays that I'm in a kind of cage, pacing up and down in it and longing to be free," he wrote. "How awful incompatibility is, and how dreadfully destructive it can be for the players in this extraordinary drama. It has all the ingredients of a Greek tragedy... I fear I'm going to need a bit of help every now and then, for which I feel rather ashamed."
But not even the support of close friends such as Emilie and Hugh van Cutsem seemed to make much difference, and Charles was sinking fast. So, one day, Emilie did the only thing she could think of that might help: she got in touch with Mrs Parker Bowles.
And she told Camilla that, in her opinion, Charles was having a nervous breakdown.
As it turned out, Emilie wasn't the only one desperately concerned about the Prince that autumn. Lady Susan Hussey had known him since he was 12, when she became a lady-in-waiting to the Queen, and had been his friend, confidante and shoulder to cry on for many years.
She had known of his misgivings and witnessed the change in Diana; on the night before the wedding, when neither Charles nor Lady Susan was able to sleep, they had stood together in her sitting room, in their night clothes, looking down the Mall at all the people and the excitement going on below, both with tears streaming down their faces.
Lady Susan was one of the few people Charles had spoken to about Diana, and she was sick with worry. She thought he was cracking up and she knew there was just one person who could save him: Camilla.
Fateful phonecall
And so Camilla phoned him.
Camilla was flattered, as anyone would be, to be told that she was the only person who might be able to lift his spirits, but it was true.
What he needed was someone who was on his side, who understood him, liked him, loved him even, who wouldn't make demands or be moody or temperamental, who was kind and warm, who would make him feel safe, boost his morale, restore his confidence and make him laugh again.
Camilla was all of those things, and because her happy childhood had given her the solid start in life that Diana had been denied, she could address the Prince's needs.
Emilie van Cutsem and Lady Susan had not exaggerated his state of mind. He was exhausted from five years of trying to handle Diana's distress, saddened beyond belief that he should have failed so spectacularly, and dangerously depressed.
"I never thought it would end up like this," he wrote. "How could I have got it all so wrong?"
And in another letter: "I am beginning to experience that kind of confusion and rundown of confidence which makes me feel temporarily miserable . . . I can't see a light at the end of a rather appalling tunnel at the moment."
When she called him, Camilla was not hoping for a renewal of their romance. Nor was that what Emilie van Cutsem and Susan Hussey had in mind when they'd asked her to intervene.
After Camilla made the first move, there were more phone calls between her and Charles. Then, after a while, he started inviting her to Highgrove - although usually in the company of her husband or other friends. Diana was never there; by then, the Prince and Princess could hardly bear to be in the same house.
As Emilie and Lady Susan had hoped, Camilla did indeed bring Charles back from the brink and give him the strength to face the world. And, eventually, what had begun as friendship and a sympathetic shoulder to cry on turned into a powerful love affair.
By that point, it must be said, Charles's marriage had irretrievably broken down, and his wife had lovers of her own - including James Hewitt, a good-looking major in the Life Guards who was now a regular visitor to Kensington Palace and Highgrove, where she would entertain occasionally when Charles was away.
He was not the first man Diana had targeted in her search for love, but their relationship lasted longer than her other affairs and she appeared to be happy until she abruptly dumped him.
Over the years, too many people have been ready to believe Charles was a bad man. He wasn't. He was an honourable man who was dealt an unplayable hand of cards.
Yes, he had always loved Camilla - in the way, perhaps, that we all carry a torch for our first love. But he took his wedding vows seriously, and had never intended to rekindle the affair.