It has been five years since King Charles pleaded with his sons after Prince Philip's funeral: ''Please, boys. Don't make my final years a misery.''
Now, as Mothering Sunday passes, some royal devotees are wondering if William and Harry might make the posthumous gift to their mother Diana by taking steps to resolve their feud.
It is not, they argue, in anyone's interest to continue their antagonism. It is as if they have failed to learn from other heir-and-spare quarrels. The imbalance of power and privilege has twisted the relationships of their forebears for at least three generations.
Circumstances differ, but that power dynamic underlies the rift between King Charles and Andrew Mountbatten-Windsor and was the context for past tensions between Queen Elizabeth II and Princess Margaret, and between George VI and Edward, Duke of Windsor after the Abdication of 1936.
Could William and Harry - self-aware men of a less hidebound generation - overcome their difficulties by showing some humanity and acknowledgement of their shared traumas?
It is a noble thought, but I argue, a forlorn hope.
Harry's departure, with Meghan Markle, to America and the allegations they raised in their interview with Oprah Winfrey in March 2021 were bold enough.
But the most compelling evidence is Harry's memoir Spare, both the content of the book and that it was published at all.
To read it is to get an insight into a man not merely hurt by the loss of his mother and his relationships with his father, brother and stepmother, but scarred by them.
© Getty ImagesThere was a sense, before publication, that Harry might somehow pull his punches. As a journalist who helped cover royal stories for The Times, I thought that publication represented such a breach of royal protocol that it seemed possible that Harry would relent. Even if he pressed ahead with the book, he might make it so anodyne that the damage would be limited.
Harry did the very opposite. He wrote about every slight, from his inferior bedroom at Balmoral to an altercation with ''Willy'' that culminated in William allegedly breaking Harry's necklace and knocking him onto his dog's bowl. Harry also made clear that he had made a choice. It was impossible, he said, to have both a contented life with Meghan and to live by the conventions of the royal family, its relationship with the press and its perpetual campaign to maintain legitimacy at the centre of British life.
© Getty ImagesIt was in some ways a brilliant memoir: it lifted the veil on the royal family with more insights in a single volume than had been garnered by decades of research by royal biographers.
It was two other things: a burning of boats and an attack on the institution of monarchy itself.
In the wake of that, what steps could either brother make towards reconciliation, if they wanted one?
One could write a long list of the issues that needed to be unpicked, from the men's relationships with each other's wives to the functioning of the Firm, but the short answer is this: it will take more than a feeling of sentiment on Mothering Sunday.
