RICHARD KAY views the poignant Mother’s Day cards to Princess Diana

They are just the kind of heart-warming cards that were being opened by mothers up and down the country yesterday: Sweet, affectionate and lovingly homemade.

But there was one significant difference in the hand-drawn greetings cards from Prince George, Princess Charlotte and Prince Louis, which were posted on the Kensington Palace Instagram account to mark Mothering Sunday.

They were not for their mother, the Duchess of Cambridge, but for their grandmother Princess Diana – a woman whom they never knew but whose influence towers over the monarchy, almost as much in death as she did herself in life.

On their own, the cards adorned with hearts, kisses and stickers for a princess who died almost 24 years ago are remarkably poignant, as was the palace’s intriguing admission that William and Kate’s children write loving messages to their paternal grandmother each year on Mother’s Day.

there was one significant difference in the hand-drawn greetings cards from Prince George, Princess Charlotte and Prince Louis, which were posted on the Kensington Palace Instagram account to mark Mothering Sunday. They were not for their mother, the Duchess of Cambridge, but for their grandmother Princess Diana

Two-year-old Prince Louis (pictured) produced a Mother’s Day card 

But this year, against the backdrop of Prince Harry and Meghan’s bitter fall-out with the Royal Family, their very existence is momentous.

For all their touching innocence, the cards seem to have a much more pointed purpose: To tilt the balance in the battle between two brothers, once so close but now estranged, over their mother’s legacy.

In years to come, historians examining this saddest of chapters in the royal story will pay particular attention to the words accompanying the pictures drawn by Prince George, seven, and his five-year-old sister Charlotte, who, remember, was given the middle name Diana after her granny and christened at the same Sandringham church where her grandmother was baptised.

George’s message reads: ‘I love you very much and think of you always,’ while Charlotte’s is perhaps even more touching. ‘Papa is missing you,’ she writes. Together, these heartfelt expressions of love and loss are not just a window into the soul of their father, who rarely allows his emotions to become public. They are also a powerful reminder that Diana had two children.

In all the storm and drama of the Oprah Winfrey interview, Harry made frequent claims about his mother. From speaking of how he could not imagine what the princess had gone through, to assertions that she would have been angry at the way he and Meghan had been treated, again and again he invoked his mother’s name.

At one stage, he even boldly stated of their departure: ‘I think she saw it coming.’ Amid the incendiary remarks about racism, complaints that their son Archie was denied a title and the almost trivial obsession over whether it was Meghan or Kate who was made to cry, many of the claims about Diana were simply overlooked.

Ever since the 20th anniversary of the princess’s death in 2017, Harry has increasingly drawn comparisons – as he sees it – between the frustrations of his life with Meghan and his mother’s unhappiness.

In years to come, historians examining this saddest of chapters in the royal story will pay particular attention to the words accompanying the pictures drawn by Prince George, seven, and his five-year-old sister Charlotte (right)

Together, these heartfelt expressions of love and loss are not just a window into the soul of their father, who rarely allows his emotions to become public. They are also a powerful reminder that Diana had two children

George’s message reads: ‘I love you very much and think of you always’

Whether it involves press intrusion or following in her charity footsteps – memorably returning to that minefield Diana walked through in Angola all those years ago – the impression he has given is that his mother is never far from his thoughts. But the running theme has been this: Both he and his mother were victims of an institution they did not respect and which did not respect them.

In doing this quite so publicly, Harry has also drawn a distinction between himself and his brother.

In that anniversary year, William did acknowledge the debt he owed his mother for helping to shape him but he has chosen not to regularly speak out about her.

By releasing such personal Mother’s Day messages yesterday, William made it clear that he will not allow Harry to weaponise Diana’s name. He is reclaiming the princess not just for himself but for his children.

It was, however, a personal intervention from a prince who patrols his and his family’s privacy extremely strictly. Family friends tell me that the decision to release the images reflects his disappointment at his brother’s behaviour.

More than anything, William has been angered by how claims about Diana have been permitted to take root in the aftermath of the Sussexes’ interview, notably the idea that she was a royal rebel. In fact, as friends of the princess have been pointing out in recent days, Diana was a patriot with a love of country and strong sense of duty who wanted to serve the institution.

William, it seems, is a far better ambassador of that concept than his brother. Publishing the cards also shines a light on the remarkable way the prince and Kate are teaching their children about their family heritage. Diana is not being airbrushed from royal life as she so tragically was in the years immediately after her death when the palace did little to celebrate her.

By releasing such personal Mother’s Day messages yesterday, William made it clear that he will not allow Harry to weaponise Diana’s name. He is reclaiming the princess not just for himself but for his children

Like many people who lose a parent at a young age, William has clearly taught his children that there is not just ‘Granny Middleton’ – Kate’s mother Carole – in their lives but Diana too.

At the same time, he also invites us to imagine something that many would find hard to summon up – the idea of Diana as a grandmother.

Were she still alive by the time of the anniversary of her 60th birthday on July 1, the princess would have had five grandchildren. So what sort of grandmother would she have been?

Stylish, naturally; hands-on certainly; and giving Mrs Middleton and Meghan’s mother Doria Ragland a run for their money.

As mother to William and Harry, Diana did not have their grandmothers to help – her own mother Frances Shand Kydd lived in a remote corner of Scotland and that left the Queen, who could hardly be a hands-on grandmother.

There is one thing she would not have allowed – the rift that has opened up so damagingly between her beloved boys who never forgot Mother’s Day.