The Princess of Wales has undergone abdominal surgery in London and will remain in hospital for up to two weeks.
Kensington Palace has said she will most likely be off royal duties for several months.
Here's everything we know about the surgery and how long the princess will need to recover.
When did she have surgery?
The Princess of Wales was admitted to hospital on Tuesday 16 January for the planned surgery, exactly a week after her 42nd birthday.
Kensington Palace confirmed on Wednesday 17 January that the procedure was successful.
Sky News understands the planned surgery was routine and the princess's condition is non-cancerous.
Which hospital is she in?
The London Clinic, a private hospital in Marylebone, central London.
The facility is one of England's largest private hospitals, treating about 23,000 inpatients a year, according to the Care Quality Commission.
It has in-patient rooms with en-suite bathrooms, air conditioning, TV and radio and Wi-Fi access.
It also has a concierge service, a café and a catering team which the hospital says bases the meals they serve on what will help each patient recover.
On its website, it adds: "We prepare all our dishes with fresh produce and, where possible, we buy our ingredients locally and source our fish sustainably.
"We have long-standing relationships with Smithfield meat market, Billingsgate, Home Counties farms and Cornish day boats."
How long will her recovery take?
Kensington Palace said on 17 January that she was expected to remain in hospital for 10 to 14 days.
After that, she will return to her home in Windsor to continue her recovery.
An exact timeframe hasn't been provided by Kensington Palace, but its statement did say that, based on current medical advice, it's unlikely she will return to public duties until after Easter.
Sky News understands her recuperation is likely to take two to three months.
Any return to royal duties for the princess will be only restarted upon medical advice that she can do so, Sky's royal correspondent Laura Bundock said.
Kate was last seen at the Royal Family's annual Christmas Day service in Sandringham.
Is William adjusting his schedule?
Sky News' royal correspondent said she understands that Prince William will also be postponing several engagements to support his wife and their three children while she is in hospital.
The couple will also not be taking part in any engagements abroad for the foreseeable future.
The prince was seen leaving the clinic at around midday on Thursday after visiting his wife.
When will we know more?
The palace said they would only provide updates on the future Queen's progress "when there is significant new information to share".
The palace said Kate is keen to "maintain as much normality for her children as possible" while she recovers.
It also said that while she "appreciates" the level of interest the public will have in her wellbeing, she hopes they will respect her desire for her personal medical information to remain private.
Expanding on the impact the surgery will have, Laura Bundock said: "Don't forget, she is very much a working royal. She undertakes, alongside Prince William, a number of engagements.
"They often look at the royal year in terms of a school calendar, describing it in terms of terms."
And of course, this would be the start of a new term, a term that would be busy with a number of engagements.
"She held this really significant international symposium at the beginning of last year where she brought together huge numbers of significant people connected to the early years, brought them under one roof to discuss ways of improving outcomes for the very youngest members of society.
"That was due to celebrate its one-year anniversary in a few weeks' time.., but for now all of this is taking a back seat. For now, all of the focus is on her recovery from this planned abdominal surgery."
The full statement from Kensington Palace
"Her Royal Highness The Princess of Wales was admitted to The London Clinic yesterday for planned abdominal surgery.
"The surgery was successful and it is expected that she will remain in hospital for 10 to 14 days, before returning home to continue her recovery.
"Based on the current medical advice, she is unlikely to return to public duties until after Easter.
"The Princess of Wales appreciates the interest this statement will generate. She hopes that the public will understand her desire to maintain as much normality for her children as possible; and her wish that her personal medical information remains private.
"Kensington Palace will, therefore, only provide updates on Her Royal Highness' progress when there is significant new information to share.
"The Princess of Wales wishes to apologise to all those concerned for the fact that she has to postpone her upcoming engagements. She looks forward to reinstating as many as possible, as soon as possible."