In many ways Dodi was perfect for Diana: warm, kind, attentive… and a wealthy man who could have provided her with the love and security she craved. They could have had a fabulous life, far away from the crowds and the paparazzi had they chosen to - on the high seas or at a remote ranch, perhaps. With Dodi’s bank account, generously filled by his father, Mohamed al Fayed, little was impossible.

She might have sought permission from the Queen, purely as a courtesy, but as Charles’s divorced wife, she was technically no longer a member of the royal family, and they could hardly have prevented her remarrying and starting a second family. William and Harry wanted to see their mother happy. They had no specific objections to Dodi, whom they had met on Diana’s first cruise with the Fayeds in July 1997.

William and Harry were boarding-school boys who split their holiday time between their divorced parents. William was already quite grown up and unlikely to take orders from his mother’s second husband. However, I think that William and Harry, Diana and Dodi would have rubbed along together rather well during their holidays on yachts and luxury villas.

Dodi might have proved a fun stepfather: he was a modern man with a glamorous past and glittering connections. The fact that he was a Muslim, although not a strict one, would scarcely have touched their lives. As heirs-in-line to the throne, William and Harry were being brought up in the Church of England. Diana fully supported this, so religious arguments against her marriage to Dodi quickly fall down.

The royal biographer Lady Colin Campbell told my programme Dangerous Indiscretions: “I think Diana's affair with Dodi was the royal family's dream come true. You see, it suited the royal family for Diana to be wound down publicly and for Charles to be wound back up, and Diana was doing with Dodi what nothing else could have done. Had she lived, her relationship with Dodi would have been an answer to the royal family's prayers."

To see that clearly, you have to look at a different possibility: if Diana had married a member of the British aristocracy, the royal family would have been forever bumping into her at formal and private events. There is considerable intertwining of friendships and families at this level. British multi-millionaires also mingle with the royals at scores of events through patronage and support for charities and other organisations, so the same thing would have happened. Would Charles and Camilla in particular have wanted to keep on colliding with Diana and her new British husband?

So, a foreign husband was actually much more desirable, especially one who might have taken Diana out of the country while Charles polished his image and established Camilla as his public partner. This was the best the royals could have hoped for. Looking at it like this, Dodi fit the bill rather well.