At Windsor this morning, crowds lined the streets to watch the Irish Guards pipe and drum their way into the castle grounds to change duties with the Welsh guards.

It was business as usual.

The palace says constitutionally the same is true for the senior royals, even if there is a temporary changing of the guard.

The King is still holding audiences with dignitaries, but he has stepped back from public-facing engagements, and there is a sense of frailty in the royal household.

Kate cancer latest: Celebrities apologise and share words of support

Former press secretary to the late Queen, Ailsa Anderson, says: “This is not a crisis, it’s a bump in the road.”

But she added: “It’s very, very difficult obviously, and unsettling, because this is an institution based on stability and continuity, and you have two key players who are going to be out of action for some time.”

The late Queen had to step up her duties when her father was diagnosed with cancer in the late 1940s. The disease accelerated her accession to the throne when he died aged just 56.

She famously said: “I need to be seen to be believed.”

Please use Chrome browser for a more accessible video player

How true that was of Princess Catherine – whose disappearance from the public eye sparked a frenzy of conspiracy theories.

And although she’s addressed those with her sobering reality, she won’t be back in the public gaze until medics say she’s fit to go.

For now, she can expect public curiosity has been replaced with sympathy, but clearly there is a lot on Prince William’s shoulders.

He will want to spend as much time as possible with Catherine and their three children, and will be with them at least for the Easter break.

But with his brother abroad and to some degree estranged, and his uncle Prince Andrew relieved of duties, there’s a dwindling pool of royal big-hitters available to hold the fort.

👉 Tap here to follow the Sky News Daily wherever you get your podcasts 👈

Constitutional expert Craig Prescott said: “There has been a slimming down.

“There has been more emphasis on a small number of royals. So when two are out of action, that is perhaps a bigger issue.”

Queen Camilla has become a key player.

She delivered a speech written by the King on his behalf, on the Isle of Man this week, and next week she’ll play his role at the Maundy Thursday service in Worcester; a key royal fixture.

The remaining support team, Princess Anne, and the Duke and Duchess of Edinburgh are likely to have more focus on them too.

Read more from Sky News:
What is preventative chemotherapy?
When will Kate return to duties in public?

Even Prince Andrew was leading the family at a recent memorial service in Windsor when William needed to be with Catherine.

This isn’t quite a crisis, but it is a test of resilience for the royals.

Keep up with all the latest news from the UK and around the world by following Sky News

Be the first to get Breaking News

Install the Sky News app for free

They hope this is only a temporary situation, but what we’ve learned in recent weeks is that while they crave privacy in illness, the public craves information.

Finding that balance is just one of many challenges ahead.

Related posts:

Former Liverpool star and TV pundit Ian St John dies ‘Holiday at home’: Govt says Britons should avoid foreign travel and enjoy ‘great places’ in UK ‘I do believe in myself’: Solskjaer insists he won’t quit after Man United thrashed by Liverpool Boy, 13, died after leaving school bus early and jumping off Tower Bridge into Thames Drinks firms warn of Christmas booze shortage due to ‘delivery chaos’ Man obsessed with COVID jailed for sending hoax bomb to vaccine factory Boy, 16, dies after falling ill at Leeds Festival – police say he may have taken ecstasy tablet Meet the grandmother tackling ‘cruel’ romance fraudsters head-on Nurse accused of murdering babies photographed card from parents of alleged victims Cost of living crisis leaves parents spending ‘less time with their children’ Girl, 2, in serious condition after being found in village pond Former doctor who was jailed for drugging partner during exorcisms ordered to pay patient he secretly recorded