Philip also expressed his concern about her bulimia and acknowledged it could have been responsible for some of her behavioural patterns. He tried to play intermediary between Diana and Charles by suggesting to her things they could do together and listing common interests they shared, which is a tried and tested method favoured by marriage guidance counsellors.

In the end, things became so bad between them, as far as Diana was concerned, that she had revealed to her friend Roberto Devorik her fears that Prince Philip was plotting to have her killed. Devorik repeated this under oath, adding that she once pointed to a picture of Prince Philip in a VIP lounge at an airport and said: ‘He really hates me and wants me to disappear.’ Her other great friend, the American billionaire deal-maker Teddy Forstmann, said: ‘She hated Prince Philip.’ She told me the same thing when I saw her at Kensington Palace shortly before her death. She explained she had warned her boys: ‘Never, never shout at anyone the way Prince Philip does.’ Without doubt, having such details of the private lives of the royal family brought out in public – not to mention such outlandish accusations made against Prince Philip – was one of the more extraordinary episodes from the royal marriage.

When the Queen came to the throne in 1952, the United Kingdom was a far different place than it is today. There were no mobile telephones, no internet, no colour televisions and no European Union; the House of Lords was made up exclusively of hereditary peers; homosexuality was illegal and punishable with a term in prison; divorced persons were not allowed into the royal enclosure at Ascot races; and the British Empire still coloured red a large part of the globe.

Throughout the tumultuous changes during her reign, the Queen has remained constant and steadfast in the execution of her duties. Despite suffering her Annus Horribilis, the divorces of three of her children and other tribulations, including the loss of the royal yacht Britannia with its crew of 120 to a tourist attraction in Edinburgh, the Queen has much to be satisfied with. Thanks to her hard work and dedication with Prince Philip, the monarchy now appears stronger than ever, with three new generations waiting in the wings. The Commonwealth, in which she has always shown a special interest, has held together remarkably well and is a force for good in a troubled world.