The Dutch have done it; the Belgians have done it; the Spanish have done it. When the time comes for Charles, Prince of Wales, to become King of Great Britain and Northern Ireland, could he be pressed to abdicate within a short space of time?
It's likely that he'll be in his 70s by the time he gets to be monarch. European royals have shown the trend to move on to a younger, more photogenic and perhaps less crabby generation, so perhaps the Brits will eventually follow?
A sensational play currently packing in audiences in London's West End, 'Charles III', is suggesting that the third King Charles will not be long on the throne.
Tim Pigott-Smith takes the role of Charles most persuasively: the narrative imagines how the new King could quickly come a cropper, because of a personal act of wilfulness - refusing to sign an act of parliament introduced by the prime minister, and then, controversially, dissolving parliament.
The act in question concerns the freedom of the press and the media - the government wants that freedom restricted, while Charles, in the play, cannot agree.
The play is so critical of the monarchy, and so upfront about royal gossip - at one point, there's a discussion speculating on Prince Harry's paternity - that my companion at Wyndham's Theatre remarked: "I'm surprised censorship hasn't been brought to bear." But the office of the Lord Chamberlain, who was the official censor in the British theatre, was abolished in 1968, so that doesn't arise. (Interesting, and quirky, historical note: the Irish theatre has never been subjected to official censorship. Pressures, maybe, but not censorship.)
Perhaps the most eyebrow-raising aspect of the drama, which is booked out (with many seats costing more than 50 quid a throw), is the kernel of the plot: that William and Kate, and particularly Kate, have strongly-held ambitions to move Charles aside, and take the throne themselves, in their prime, rather like the Euro-royals.
Kate, stunningly played by Lydia Wilson, is seen as a closet feminist with a steely ambition, determined to oust her elderly father-in-law. She advances the explanation that in the age of media image, a beautiful young couple are far more acceptable to the public than an old geezer and his mumsy wife, Camilla. There is also an appearance by the ghost of Diana, like a Shakespearean spectre, warning that she always predicted this would come to pass and Charles would never be king. (In the play, he inherits the throne but is never crowned.)
Could it happen just as the playwright Mike Bartlett seems to predict? Constitutionally, yes. A British monarch may refuse to give his assent to any act of parliament, though none has done so since the reign of William IV (died 1837). As far as we know, Elizabeth II has never raised any objection to any of the acts of parliament put in front of her, though some of them, surely, were not entirely to her taste, and usually reliable sources have indicated that she baulked at some of Margaret Thatcher's policies.
But that's one of the points of 'Charles III': a monarchy's popularity (Elizabeth's is currently running at 77pc) depends on the personality of the incumbent. The British monarchy is popular while Elizabeth is at the helm, but what happens afterwards?
In the programme notes, the commentator Tim Stanley writes that the actual problem with Charles is that he "has never grasped the constitutional limits of his role in the way that his mother has". Charles has been outspoken in his opinions about environmentalism, organic farming and architecture: he has also corresponded with government ministers in a manner that some regard as overstepping his constitutional role.
It's not the ghost of Diana that is raised here, but the ghost of Cromwell, who introduced the idea that parliament was sovereign, and the monarch may reign but not rule. If Charles does overstep his constitutional role as king, then there could be trouble. The play's programme also suggests that: "Charles's decision to marry - some would say his insistence on marrying - his former mistress Camilla Parker Bowles in 2005… was an example of the kind of wilfulness that defines Charles's character and distinguishes him from the Queen... Partly as a consequence of Charles's reputation, the monarchy will change substantially after Elizabeth dies."
The well-heeled London audience laps all this up, but I couldn't quite believe the basic premise. Kate and William plotting to overthrow Charles? Harry running off with a sexy republican art student got up in Doc Martens? I don't think so. But listening to the conversation of others after the show, many clearly thought 'Charles III' was a persuasive projection of the future of the monarchy. Family schemes and acts of betrayal are, after all, the stuff of Shakespearean plots.
It would be a somewhat hurtful drama for Charles (and Camilla) to watch, but perhaps fortunately for them, they won't watch it as they tend to be protected from, or ignore, that which is threatening. And being portrayed unflatteringly in the public realm is part of their gig.
Moreover, there are plenty of loyal subjects who have a very high regard for the Prince of Wales, and full confidence in his character, including my English husband, who always said he would far rather be ruled by King Charles than by any pesky politician.