Even the most charitable royal watchers would suspect an ulterior motive behind Prince Harry’s birthday greetings to his father, the King, this week.

The conversation between the pair, believed to be their first communication in months, is said to have gone so well that further chats have been scheduled.

What’s more, Meghan got in on the act, too, wishing her father-in-law many happy returns, and the couple’s children, Archie and Lilibet, were recorded singing happy birthday to their grandfather, according to reports.

The rapprochement, which seemed to spring from nowhere, marks a thawing of the froideur sparked by the Sussexes’ exit from royal life and subsequent whinge fest against the Windsors, in television interviews, a Netflix series and Harry’s memoir, Spare.

But what does it mean and is it for real? The first thing to note is Charles’s capacity for forgiveness, the product of a father’s unconditional love for his son, no doubt, but also a reflection of his inherent kindness.

Whatever cynical reasons the King might have for accepting Harry’s olive branch – the peace offering appears to have come from California – everything we know about Charles suggests he would have been thrilled to have his youngest boy back in the fold.

And delighted to see his long-lost grandchildren, removed from their relatives by embittered and embattled parents.

The British public, the royalists at least, may forever bear a grudge against Harry and Meghan for all the dirt they have dished and the pain they have inflicted, but Charles can afford to be magnanimous.

Since the Coronation his stock has continued to rise, with his focus on causes close to his heart and successful tours of Germany, France and Kenya cementing his and Camilla’s popularity at home and abroad.

He has so far proved himself to be equal to his destiny, managing better than many of us expected the transition from his much-loved mother’s lengthy reign to his own, necessarily different take on the monarchy.

Healing the rift with Harry will be the icing on his 75th birthday cake. But he must surely be wondering, as are the rest of us, what the scheming Sussexes are up to.

It is not an exaggeration to call their barrage of barbs against the royals a concerted campaign, with no let-up, until, quite suddenly, now.

But where has it got them? For all the embarrassment their soap opera has caused, they have failed to rock the royal boat in any meaningful way. 

Charles, Camilla, William and Kate (these two are most certainly not included in the Montecito kiss-and-make-up) have emerged in the late Queen’s wake as a formidable foursome.

It must be galling for Harry and Meghan, but nothing they say or do to undermine the ‘firm’ sticks. In fact, it is they who have suffered a loss of status and credibility, initially in Britain but now also in the US, where any veneer of royal gloss has been eroded by their spite.

The further they have alienated themselves from the family, the more they have forfeited their social cachet. Time, then, for an about turn.

First, the call to Charles, which was reportedly put in the public domain by the Sussexes, apparently keen to demonstrate a cessation of hostilities.

Just as significant is the couple’s distancing of themselves from their one-time cheerleader, chief royal baiter Omid Scobie, whose new biography, Endgame, cashes in on the Windsor fall-out.

Harry and Meghan want it to be known that they had nothing to do with the book, due out this month, after an excerpt attacking, in particular, William, was published in an American magazine.

The couple previously denied they had helped Scobie with his first book, Finding Freedom, but Meghan was later forced to admit during a court hearing that she had forgotten she had provided the author with “briefing notes”.

Scobie, a self-styled royal reporter, has been a key fixture of Team Sussex, their go-to trusty mouthpiece, but now it looks like he is being dropped as the pair insist they are not “affiliated” with him.

Scobie has been closer than most and it will be interesting to see if, once ejected from the camp, he has another, less Sussex-centric, book in him.

As for the couple’s future, if they mean to rescue their brand by burnishing their royal credentials anew, their next move will be challenging.

For Harry, patching up his problems with the old man is the easy bit. William will not be so accommodating.

But if the Duke, who cuts a lonely figure in exile, wants a little of his British life back, and Meghan is on a mission to recapture her celebrity standing, William – and Kate – must be won over. That will take more than a phone call and a cheesy video of the kids.

Write to us with your comments to be considered for publication at letters@reaction.life