With two statements, 46 days apart, the trajectory of royal history has shifted just a little. The King revealed he needed treatment for cancer then the Princess of Wales followed suit.
Their diagnosis is an unexpected and unhappy coincidence but it is one that will, at least, bring some companionship for two leading players of the modern monarchy and a father and daughter-in-law who can lean on each other more than ever.
They have “always been close”, sources said this weekend but their newfound bond has been “comforting and reassuring” for both.
Seemingly out of the blue, the King and Princess have found themselves at the heart of a Royal family now forged in adversity: not in palaces or castles but on the wards of a London hospital.
The pair are known to have spent time together at the London Clinic, where they were both inpatients towards the end of January.
Staying on the same floor of the hospital, in a sealed-off zone protected by security, the two members of the Royal family were shielded from curious eyes and able to spend time talking as they dealt with their unfolding medical diagnoses.
The King, who walked in and out of hospital initially for a procedure to correct symptoms of an enlarged prostate, made the short stroll along the corridor to see his daughter-in-law multiple times after her abdominal surgery, when he could.
“I think it was nice for them,” said a source, simply.
Since then, both have received confirmation that their health issues were more serious than originally feared. Both have cancer, both are undergoing treatment, both say they are “doing well” and both plan to be back in action.
Their parallel journey, unknown as it was to everyone outside their very innermost circle, is reflected in the King’s most recent, poignant statement on Friday night.
The King, said a spokesman shortly after the Princess’s news was announced, is “so proud of Catherine for her courage” as she told the world she is having treatment for cancer, calling her his “beloved daughter-in-law” with whom he is in “close contact”.
He will continue to offer “love and support” to her, his son, and three young grandchildren, it was said.
If it is difficult to recall such personal and warm words from a monarch. They came shortly after the King and Princess sat down for a Windsor Castle lunch together.
Their conversation is unknown, though it was alleged to be “emotional”. An initial report of the meeting in the Sun on Sunday was confirmed by palace sources, who said the pair “did have lunch” but declined to detail their conversation: “Only they know what they talked about.”
The next day, Friday, the Princess authorised the release of a video, shot at Windsor on Wednesday of that week by BBC Studios, in which she spoke movingly of how she has reassured her children she is “going to be OK”.
The message was entirely hers as was the decision to film it. “She held the pen,” said an aide.
Another source said: “Every human being is totally different in how they react to this type of news. First it’s her processing it, then her husband processing it, then getting their three children to a point where they can process it.
“And then, in her case, sharing it with the entire world.”
Buckingham Palace and Kensington Palace have both confirmed that the King and Queen were made aware of the Princess’ diagnosis before she took the remarkable step of announcing it personally via video.
The relationship has not always been quite so clear cut. The feelings of the much younger Prince William and Prince Harry towards their stepmother have been well documented.
Since his marriage, the Prince of Wales has focused closely on his own young family unit: Prince George, Princess Charlotte and Prince Louis at the centre of his world with the Princess as its “lynchpin”.
Over the years, that intergenerational relationship has improved drastically. The King and his heir have been in “lock step” for some years, insiders have said, with a stronger working dynamic than ever before.
Since the Prince and Princess moved to Windsor, the King is said to have spent more off-duty time with his grandchildren in a shift greatly encouraged by the family-minded Princess.
As in all families, serious illness will focus Royal minds even further.
“They have a very strong, genuinely warm relationship,” one source said of the two remaining generations, the King and Queen and the Prince and Princess.
Another said this weekend: “What we’ve seen in recent weeks is that because they are both going through the same health experience, it’s cemented that bond.”
The King is said to have been keen to give his elder son the time and space he needed to come to terms with the Princess’s illness, with the Royal households insisting since early February that the Prince will not be expected to “step up” to take on additional duties for the monarch.
As pressure on the Prince increased, so the palaces stood firm that he was to be left in peace to look after his wife, without letting on the reason why that was so necessary.
“The vast majority of people want them to be left alone,” a source insisted last week. “Fundamentally there has been a groundswell of support. There has been huge sympathy and great support.”
That sympathy and support has only increased following news of the double diagnosis. It also brings practical challenges.
If years ago there were three full generations of working Royals headed by Queen Elizabeth II and Prince Philip, much has been made of the “slimmed down” modern monarchy of the Carolean era.
With two of the most senior members out of action in public – the King working behind closed doors and the Princess concentrating on her health – no-one is contesting that the span of royal engagements, for now, will feel different.
But there is hope for recovery, in all sense.
One palace source said that illness brought with it the opportunity to do more, eventually, in their public duties.
The King, Queen, Prince and Princess have all supported cancer charities, patients and affected families through patronages, engagements and keeping in personal contact with individuals over the years.
“They have chosen to be honest [about diagnosis] in the hope it would support other families,” one friend said. “After all, what is more relatable than facing an illness that so many others will have experience of?”
For now, the King and Princess will take different approaches to suit their different roles.
The King, as Head of State, continues his constitutional duties largely from home, protected from infection risk present at walkabouts and large public engagements as he completes his own treatment.
Those who have seen him report that he has maintained his positive outlook throughout his treatment. “His doctors are optimistic, the King is in a good mood,” they said of his own health. “He is raring to go on all fronts.”
The Princess, who has said she looks forward to getting back to work when she is able, will remain out of the public eye.
They will, it is said, keep in close touch. With the Prince and Princess staying at their Norfolk home of Anmer for the three-week Easter holidays, they will not be far from Sandringham should the Royal family diaries overlap.
The link between King and Princess is of course the Prince, who has hunkered down in the most important supporting role possible.
“You can imagine what he must personally be going through,” said one friend. “His wife is the centre of his world. His father is ill. He has got a lot on his plate.”
Despite no-one wanting to talk about it, one observer concedes, the Prince “knows only too well what lies in front of him one day”.
In the coming weeks and months, the only role that matters is that of husband, father and son.
The King, having seen the Princess at her most vulnerable, will understand.
He knows better than anyone how the monarchy’s fate can ride on the right balance of “Royal” and “family”.
Historically, it is the first word that has stood the Windsors apart in strength and good stead.
As they face their greatest personal challenge in decades, the focus will rightly turn to the second: family.