Saturday 14 May 2022 10:10 PM The inside story of Prince Charles's 23-year battle to persuade the Queen to ... trends now

His bombshell book Diana: Her True Story forged Andrew Morton's reputation as a Royal biographer. 

Here, in the second part of our serialisation of his new biography of the Queen, which started in yesterday's Daily Mail, he recounts her difficult relationship with Camilla Parker Bowles.

A deep chill settled over the Queen's relationship with Camilla Parker Bowles in the late 1970s that seemed unlikely ever to lift. 

At the time, Prince Charles was making efforts to find a suitable wife, though at least two candidates – Lord Mountbatten's granddaughter Amanda Knatchbull and the Duke of Wellington's daughter Jane Wellesley – turned him down when he proposed.

Yet all the while, his heart belonged to Camilla, whose husband Andrew was a major in a Household regiment, the Blues and Royals. The Prince's continued pursuit of a married woman, however, had offended many of Andrew's fellow officers.

After discreet conversations between the regiment and Buckingham Palace, senior Royal officials formally informed the Queen that the Blues and Royals were 'unhappy' that her son was sleeping with a major's wife.

The Queen made no comment nor, crucially, did she speak to her son about his behaviour, let alone to Camilla – with whom she had once been on friendly terms. 

Such a confrontation would, according to courtiers, have been totally out of character. Much rather an hour with her red boxes, which acted as the Monarch's security blanket, than address such an intimate family issue.

She did, however, put out the word that Mrs Parker Bowles was not to be invited to any Royal events, and that included Charles's 30th birthday party at Buckingham Palace in 1978. The Queen Mother followed suit.

Camilla had, in effect, been 'cancelled' by the highest in the land, and there was nothing her Royal lover could do about it.

In any case, she appeared to have been little more than a temporary sideshow once Charles settled on 19-year-old Diana Spencer as his bride.

Five years into their troubled marriage, however, it was a different matter. By July 1986, both had found comfort in the arms of other lovers. But while Diana would go on to have a number of affairs, Charles had eyes for only one woman: Mrs Parker Bowles.

Somewhat naively, the Princess was frustrated that the Queen never intervened to end her son's adulterous relationship. Had Diana understood the Queen's deep loathing for any kind of direct confrontation, she might have realised it was the last thing her mother-in-law would ever do.

Well before Diana's death in 1997, Charles had started laying the groundwork for Camilla's continuing presence in his life.

Publicly, he declared in a 1994 TV documentary that she was a good friend and would remain so in the future. Privately, he encouraged her to take on the role of mistress of Highgrove. 

This did not please the Queen, who wanted Camilla gone – an uncompromising view shared by her senior officials, notably her private secretary Sir Robert Fellowes (whose wife was Diana's sister).

Charles's desire for self-fulfilment, they felt, was in danger of jeopardising the Monarchy.

As for the Queen, she believed he simply hadn't spent enough time working on his relationship with Diana before going back to Camilla's soothing ministrations. 

However difficult the Princess had been, and the Sovereign knew all about her wayward behaviour, she'd deserved more than the four or so years he'd devoted to married life before cutting loose.

In fairness, though, not even the Queen could be certain that Charles and Diana would have remained together, had his lover not been on the scene.

Camilla's divorce in 1995 changed nothing, as far as the Monarch was concerned. Nor did she soften towards her son's mistress after Diana's death two years later.

Charles, for his part, made it abundantly clear to his mother that Camilla wasn't going anywhere, and his obdurate attitude inevitably placed St James's Palace and Buckingham Palace on a collision course.

Few attending his official 50th birthday party, held at Buckingham Palace in November 1998, would have sensed the familial tension in the air. 

An estimated 850 guests, including Prime Minister Tony Blair and former premier Margaret Thatcher, toasted his life and achievements in the presence of the Queen and Prince Philip.

In their speeches to the gathering, Her Majesty praised her 'darling' son for his 'diligence, compassion and leadership', while Charles referred to her as 'Mummy' – a description that always received an amused reaction, so he tended to use it often. Behind the public smiles, though, relations between 'Mummy' and 'Darling' could not have been worse.

The first issue concerned the thudding absence of Mrs Parker Bowles, who'd deliberately been left off the invitation list by the Queen. 

The second was an ITV television documentary, broadcast to coincide with the Prince's birthday, in which a 'senior Royal aide' was reported to have claimed Charles wanted a slimmed-down Monarchy and would be 'privately delighted' if the Queen abdicated.