This can only be described as an abdication. Meghan and Harry have in effect withdrawn from their royal duties and will spend a large part of their future lives in North America.

It is hard not to feel history repeating itself. Even the wedding car that drove the future Duchess of Sussex to be married to Prince Harry in St George's Chapel, Windsor, was the very car that drove Wallis Simpson to attend the funeral of her husband, the former Edward VIII.

In 1936, the immensely popular, lovable new king had renounced the throne because he wanted to marry Mrs Simpson, an American divorcee.

That event is seared into the consciousness of the Royal Family: it has obsessed them ever since.

The explanation given at the time was that Edward was to be the head of the Church of England, which forbade divorce.

But behind this convenient excuse, the Establishment wanted rid of Edward VIII. They found his fascist-sympathising politics dodgy and they feared his outspoken, witty wife.

Prince Harry and Meghan Markle Prince Harry and Meghan Markle during their engagement announcement at Kensington Palace in November 2017

They felt much safer with the shy, stammering Duke of York and his homely, aristocratic Scottish wife, who became our beloved Queen Mum.

Harry and Meghan's 'abdication' is of course nowhere near as dramatic as Edward VIII's was 84 years ago.

Yet there seems little doubt that their decision has shocked Buckingham Palace and the wider Royal Family as it has shocked the country.

It has been suggested that Meghan and Harry made their bombshell announcement without consulting the Queen.

If true, that is, in my view, an atrocious lapse of judgment. The wording from the Palace last night, that 'these are complicated issues that will take time to work through', hints that the decision to abandon their royal duties is perhaps not as final as Meghan and Harry might wish it to be.

Yet, for all that, I believe that this may prove to be for the best.

Unlike the Abdication of 1936, which really was an existential crisis for the Royal Family and which led to the entirely unexpected ascension of George VI to the throne, this 'abdication' will strengthen the institution of the monarchy.

When Harry and Meghan had their very public wedding – Meghan, like Wallis, was 34 when she met her future royal husband – many of us felt that a new chapter had been opened in the history of the Windsors.

Prince Harry and Meghan, the Duchess of Sussex visit to Cape Town, South Africa, last September (right) and the Duke and Duchess of Windsor standing on stone steps in an undated photo (left)

Here was a breath of fresh air: a feminist, mixed-race American who had established a career for herself as an actress, joining a slightly stuffy English family. Yet the love affair between Meghan and the British press was doomed to be short-lived.

The truth is that this charming, intelligent, beautiful woman hadn't a clue what the monarchy really is, or what role minor members of the Royal Family have to play in public life.

For his part, Harry perhaps didn't fully understand his own role as a younger son. Both seemed oblivious to the fact that the British monarchy is a delicate constitutional miracle, not a vehicle for its members to press home their views on the subjects that interest them, however noble.

A minor royal such as Harry or Meghan (Harry is now sixth in line to the throne) essentially exists to be on standby for public engagements that senior royals are too busy to fulfil. They must also keep their views private.

Yet Meghan, as befitting her role as a socially conscious and ambitious career woman, wanted her views on everything from climate change to women's rights to be centre stage.

Meghan Markle and mother Doria Ragland leaving Cliveden House Hotel en route to St George's Chapel at Windsor Castle for her wedding in 2018

Sooner or later, this lovable pair – the playboy prince with heroic war service behind him and the glamorous Californian – were perhaps always going to come a cropper.

This sort-of abdication, this sort-of exile, allows Harry and Meghan to continue supporting their favourite charities and promoting the causes in which they so passionately believe.

Their millions of fans around the world will go on adoring them wherever they appear. Meanwhile, on this side of the Atlantic, the Windsor show goes on.

As the Queen's prodigiously long reign comes slowly to an end, it has become ever clearer that the monarchy is a central part of our constitution and our life as a nation.

But, as Prince Andrew's disgrace last year made plain, we do not want that treasured institution to be confused by the low – or indeed high – view we might have, as readers of newspapers and followers of the media, of individual minor royals. There are now very many minor royals, living sensible lives away from the glare of the media.

That is how it should be. All that matters for the monarchy to flourish is for the succession to work.

The wedding car that drove the future Duchess of Sussex to be married to Prince Harry in St George's Chapel, Windsor, was the very car (above) that drove Wallis Simpson to attend the funeral of her husband, the former Edward VIII

One day the Queen will be succeeded. King Charles III will presumably have a short reign, but few people now doubt his suitability for the role; objections to the marital status of the Duchess of Cornwall are nowadays few.

Next come Prince William and Kate Middleton, who have been exemplary, behaving with good humour, loyalty and dignity on all occasions, and providing us with an heir to this wonderful institution.

That's enough. We do not need 'the Royal Family', that rather bogus concept invented by Prince Albert, with all its extended members compelled to feel as if they are on parade.

We in turn – especially we of the Press – have felt it was our right to pry into their personal affairs, for the very good reason that, until recently, so many of them were living on the Civil List, paid for by you and me.

Only a pared-down royal family will allow this institution to survive long into this century. Only Princes Charles, William and George are preparing for – and being groomed to – wear the crown. All the other figures are walk-on parts in the royal soap opera.

So, farewell, Harry and Meghan. And good luck. Your departure will give you the chance to live your lives without the awkward sense that you have no clear role to play in British public life.

And – as you would surely wish – it will strengthen the institution from which you have so dramatically stepped down.