When the Queen and Prince Philip celebrate their 70th wedding anniversary on November 20, they are – in one sense – certainly making history. This is the longest royal marriage in the long annals of the British monarchy.

But in another sense Prince Philip, for almost seven decades now, has been standing where a small band of men have stood before him – two steps behind a reigning queen, and not finding the position easy.

Her husband, said Queen Elizabeth II in her Golden Wedding speech, ‘has, quite simply, been my strength and stay all these years’ . There is no reason to doubt her. But her statement is remarkable for what it didn’t actually say . . ,

That the Queen is the one who needs support, because of the prominence of her position. That her husband’s role is to be a background presence – just as, in other traditional marriages, a wife’s would be. That he has managed to put himself and his own career second – hard for a man his background and temperament, surely

Prince Albert, Queen Victoria’s consort, once wrote that his ‘most peculiar and delicate position’ required ‘that the husband should entirely sink his own individual existence in that of his wife’. Prince Philip has not entirely done that, and just as well, maybe. He has kept his own interests in science and technology, in the Duke of Edinburgh’s Award scheme which has helped young people in more than 140 countries. He probably needed to, in order to keep his sanity.

Unlike Albert, who married an already-reigning Queen, Philip can’t have known the deal he was getting, precisely. When he and Princess Elizabeth married in 1947, he might reasonably have hoped for years in which to pursue his own flourishing naval career. But George VI’s failing health put paid to that, even before Elizabeth acceded to her father’s throne early in 1952.

That said, there are some remarkable similarities between Prince Philip’s and Prince Albert’s positions – yes, and those of the men who came before them, too. The choice of consort for a female monarch has always been a vexed one – the choice of consort for any powerful woman, maybe.

Back in the days of the Tudor queens, the power a foreign husband might wield over his spouse was often held to rule out a female monarch. It’s one of the concerns that kept Elizabeth I a Virgin Queen. Perhaps she remembered how the English people hated her sister Mary’s Spanish husband – or she looked north, across the Scottish border, and saw how first Darnley then Bothwell expected to lord it over another, Stuart, Mary.

There were huge concerns over Prince Albert’s Germanic foreignness – rumours even, in the days of the Crimean War, that he had been locked in the Tower as a foreign spy. And in 1947 – so shortly after the end of the Second World War – some of the questions about ‘Phil the Greek’ centred on his family’s connections with the Nazis.

The complaints of some MPs about the cost of Elizabeth and Philip’s wedding echoed those about the income Victoria and Albert would enjoy. But in fact the wedding was hailed as, in Winston Churchill’s words, ‘a flash of colour on the hard road we have to travel’. The fact that for the first time newsreel cameras were allowed to follow the royal wedding party into Westminster Abbey itself was an omen, perhaps, of the modernising role Prince Philip would play within the royal family.

At Queen Elizabeth’s coronation in 1953, Prince Philip was the first to swear allegiance to her on bended knee. He swore to be her ‘liege man of life and limb’, and if he should outlive his wife, he’ll have to swear the same oath to his own son, presumably.

When the decision was taken that the Queen’s children should keep her name of Windsor, he cursed that he was ‘just a bloody amoeba’. There would be other issues over what Philip’s role was supposed to be.

Before his wife’s accession, Prince Philip said, whatever they did was done together, and ‘I suppose I naturally filled the principal position’. After it, by contrast, he would not be privy to the red boxes of state papers, or present at the Queen’s weekly audiences with her Prime Ministers. Just so had Victoria originally limited Albert’s role to ‘dealing with the blotting paper’.

But Victoria’s many pregnancies gave Albert his chance, so that he was able to become not only ‘the natural head of the family’ but Victoria’s ‘sole confidential advisor in politics’. Philip has had no such opportunity. But he found a way to accommodate himself to the situation.

As his grandson Prince William says, he ‘totally put his personal career aside to support her, and he never takes the limelight, never oversteps the mark.’ He has cheered and encouraged the Queen into the crowd-pleasing aspect of her duties, which at first she did not find easy. In that, he is due some share of the credit for the recent resurgence in the popularity of the monarchy.

But the Duke of Edinburgh is almost five years older than his wife, and perhaps in less robust health than she. Prince Albert’s death threw Queen Victoria into a hysterical mourning that endured for decades. Queen Elizabeth, no doubt, would meet any loss stoically. But that loss would be immense, for her – and for us too, maybe. It’s only after the Duke is gone that we are likely to appreciate him properly. To realize that this seven-decade partnership really has been extraordinary.

Sarah Gristwood is the author of Elizabeth: The Queen and the Crown