With each day that passes, the fallout between William and Harry is looking more permanent.
These are the brothers who clowned around, trained to fly helicopters together and shared experiences from a traumatic childhood that no one else could know.
They had each other’s backs, they were always there for one another. Princes, brothers and best friends.
Just a few years ago, before Harry met Meghan, they were living alongside one another at Kensington Palace; Harry popping into William and Kate’s apartment to play with their children and raid the fridge.
Today they are living nearly 6,000 miles apart and barely speaking. And the bust-up is painfully public.
In any family when siblings stop talking to one another it is a tragedy but this has wider implications.
The Fab Four, as they were dubbed after Meghan joined, had everything going for them. They had charm, charisma, humour and a great rapport with the public – and, apparently, each other.
They seemed intent on using their privilege and their titles to help others: the forgotten in society, the wounded, the disadvantaged.
Taking on the many of the causes their mother championed, they seemed invincible; and with the four of them together, the long-term future of the monarchy – lean and approachable – seemed certain.
So what went so disastrously wrong? At first it seemed it was the wives – not each other’s cup of tea.
But it was more than that. There were tensions between the two princes before Meghan came into the picture.
They were beginning to tread on each other’s toes with the charitable work.
Then Harry met Meghan and was bowled over. He was talking about marriage within just a few months, and William, as a concerned older brother, questioned whether it might all be happening too quickly.
It was a reasonable question and one that a loving brother was right to ask. Their parents had rushed into their disastrous marriage within a year of meeting and scarcely knew one another when walking up the aisle.
But Harry, head over heels in love, and ever impulsive, wasn’t thinking rationally. He took his brother’s intentions amiss. He assumed that William didn’t like or approve of Meghan and that was that.
William wasn’t the only one who wondered whether Harry was moving too quickly. Close friends expressed their concern too and they too were eased out of favour.
But was this enough to make Harry and Meghan feel compelled to leave the country and turn their backs on Britain? I don’t think so.
I think there is an element of history repeating itself.
When their mother became Princess of Wales nearly 40 years ago, aged just 20, she seemed the perfect wife for Prince Charles. She was an aristocrat, her father had worked for the Queen and before her father inherited the stately pile and the earldom, they had lived on the Sandringham estate.
She was comfortable around royalty and understood protocols.
What Charles didn’t know was that Diana had been badly traumatised by her parents’ ugly divorce. Her mother had left home when she was six and, to her mother’s great distress, custody of Diana and her siblings was granted to their father.
Diana grew up feeling unloved. Those terrible feelings blighted the rest of her life and were a significant factor in the break-up of the marriage. William and Harry, therefore, grew up with little understanding of what a happy family looks like.
For years Harry had been unlucky in love. One long-term girlfriend, Chelsea Davy, couldn’t bear the media intrusion.
The other serious contender was Cressida Bonas. Her parents divorced when she was young and she has a complicated multitude of half-siblings. One of the factors in Cressida and Harry’s split was the acute awareness that neither of them knew what a happy family looked like.
I am not sure that the same awareness crossed Harry’s mind when he was swept off his feet by Meghan Markle, for not only did she come from a broken home, with messy relationships with her half-siblings, she already had a failed marriage.
Being married to a royal, with all the publicity and scrutiny that’s involved – apart from the weird nature of the job – is not easy.
What gives Kate such strength is that she comes from a solid, stable, happy home. She has parents and siblings to support her and to keep her feet on the ground and to inject normality into an abnormal life.
William folded into the Middleton family from the start. He delighted in their closeness, in the relaxed atmosphere in the house, walks to the pub and the humdrum nature of their daily lives – all were very new to him.
And because Kate had, and still has, the stability of that functioning family to support her, she has navigated the minefield of life as a royal and as a mother.
Diana, by contrast, had no firm foundations. In public she played the part but less so in private and she had no one to turn to for support.
And neither did Meghan. The only member of her fractured family she seems to be talking to is her mother and she was thousands of miles away when Meghan ran into trouble.
Harry is very like his mother and he has always been impulsive in the way she was. My guess is that Meghan was unhappy and missing home. He did what he thought would make her happy without thinking it through or discussing it with the family.
Meghan had been through huge life changes in a very short space of time. She had given up her job, left her country, left her support network of friends and moved to Britain, married – into an unusual and some would say dysfunctional family – taken on a new and very unusual job and had a baby.
At first, she seemed to be relishing her new life. And the British public took to her with great enthusiasm.
She won hearts and minds with her informal style. “Hi”, she would say on walkabouts, “my name is Meghan” – as if they didn’t know. Their wedding was the most joyous occasion and what could have been better for the Royal Family than to have a person of colour among their number?
It made the institution more relevant to a wide swathe of the population.
Just imagine the impact her contribution to the Black Lives Matter movement could have had if she had been speaking from within the Royal Family. I suspect Meghan is more complicated than she looks and Harry is determined to protect her whatever the cost.