It was Philip who had Sarah banned from all the royal homes, including at Christmas time. Despite the Queen’s affection for Prince Andrew’s ex-wife, she would not go her against her husband’s wishes on the matter and has never done so. She tried to persuade Philip to change his mind and allow Sarah to spend part of each summer’s holiday at Balmoral, but he would not budge. In domestic situations such as these, however, the Queen was not above a little underhand subterfuge, and when Philip left Scotland for a few days she would telephone the duchess and say, ‘Here’s your chance – come up now.’

It did not take long for Philip to find out that Sarah had been there, of course. He was not unduly angry – after seventy years of marriage, the Queen and her husband have settled into a state of benevolent compromise on most issues. He simply repeated what he had said before, which was that she had taken the decision to walk out on the royal family, so out she should stay.

His initial attitude to Diana was more ambivalent. Or it was for a while, and then he changed his mind. And that added to the pressure under which the Queen found herself. Like the Queen, he recognised the prominent role in the royal family that Diana had carved out for herself, but he did not like it. This most fiery of men has always been careful to follow tradition and defer to his sovereign on all matters outside the household, even though she happened to be his wife. ‘His constant job is looking after the Queen,’ said his friend and former private secretary, Mike Parker. ‘He told me his job first, second and last was never to let her down.’

It was inevitable, given his belief in the duty of consort to his wife, that he would find himself at odds with the woman who put her personal happiness before the job of being consort to her husband. When the Queen expressed her sympathy with Diana’s predicament, Philip was incensed. As always, he articulated himself forcefully. He accused his wife of ‘procrastinating’ on the question of whether Charles and Diana should divorce. Perhaps unsurprisingly, Princess Anne took her father’s side, as did Prince Edward.

The Queen’s sympathy for Diana’s position was finally put to the sword by the Panorama interview which was broadcast on 20 November 1995. Watched by an audience of 15 million in Britain alone, Diana chose the vehicle of television to declare that there were three people in her marriage. She said she wanted to be Queen of People’s Hearts and she inferred her husband was unfit to be King. ‘Because I know the character,’ she said. ‘I would think the top job, as I call it, would bring enormous limitations to him and I don’t know whether he could adapt to that.’