Kate Middleton has announced she is having treatment for cancer and spoken of an “incredibly tough couple of months for our entire family”.
The shock health news follows Britain's King Charles's diagnosis with cancer, with the condition discovered during his recent hospital treatment.
Here is the timeline of the health troubles facing the royal family.
In her last public appearance before the news of her hospital treatment, Kate was seen on Christmas Day in Sandringham walking to church with the rest of her family.
She held hands with her daughter Charlotte and looked happy and relaxed as she grinned at well-wishers while strolling to the service at St Mary Magdalene Church in Norfolk.
Kate turned 42 on January 9, and while the monarchy’s official social media accounts celebrated the day with a behind the scenes photo of Kate at the coronation, there was unusually no customary response from Kensington Palace this year thanking well-wishers for their messages.
Kate is secretly admitted to The London Clinic and undergoes abdominal surgery.
She attends the clinic rather than King Edward VII’s Hospital which is usually the go-to establishment for royal medical matters.
2pm – Kensington Palace announces the princess’s operation and says she will remain in the private hospital for 10-14 days.
She is not expected to return to duties until after Easter, taking up to three months to recover.
Prince William steps back from his official duties temporarily to care of his wife and children.
The exact nature of Kate’s condition is kept private, but it is not cancerous and Kensington Palace says the planned procedure was successful.
3.25pm – Buckingham Palace announces that Charles, 75, is to have treatment for a benign enlarged prostate and will be admitted to hospital in a few days.
A source later says the princess is “doing well”.
William spends time at his wife’s bedside, driving himself away from the back entrance during the low-key, private visit.
A serious-looking William was seen leaving the private The London Clinic at about 12.35pm.
Camilla says the King is “fine” and “looking forward to getting back to work” during a visit to the Aberdeen Art Gallery.
Charles flies back from Scotland with Camilla and heads to his Sandringham estate in Norfolk to rest ahead of the procedure.
It is announced that the King’s former sister-in-law, Sarah, Duchess of York, has malignant melanoma, a form of skin cancer.
It is less than a year since the duchess, 64, was diagnosed with breast cancer and had a mastectomy and reconstructive surgery.
Camilla tells 86-year-old well-wisher Jessie Jackson that Charles is “fine”, and thanks her for asking, while she carries out engagements in Swindon.
Sarah, Duchess of York, meanwhile, describes her shock at having skin cancer but says she is in “good spirits” and “grateful for the many messages of love and support”, in a post on Instagram.
Kate’s hospital stay passes the one-week mark.
Camilla urges Camilla to take it easy.
An insider told The Sun: “The Queen has told him he needs to slow down a bit.”
Charles carried out behind the scenes official duties, meeting academics from Cambridge University at Sandringham House.
He arrives back in London from Norfolk ready for his treatment.
Charles, with Camilla at his side, is admitted to the London Clinic for treatment for an enlarged prostate and also visits Kate, who is recovering in the same hospital.
Charles took time to visit his daughter-in-law , who is on the 11th day of her hospital stay after undergoing a successful major operation.
Charles King is discharged from hospital and waves at well-wishers.
Kate leaves the clinic the same day to continue her recovery at home.
Camilla says Charles is “getting on, doing his best” as she opened a Maggie’s cancer support centre at the Royal Free Hospital in London.
Charles and Camilla attend church in Sandringham, with Charles waving at well-wishers.
Kensington Palace confirms that William is returning to official duties this week, beginning with an investiture.
6pm – Buckingham Palace announces that Charles has a form of cancer, but not prostate cancer, and has started treatment as an outpatient.
He will not carry out public-facing duties, but will carry on with behind the scenes state business and official papers.
William speaks about the King’s cancer diagnosis for the first time and thanked the public for their “kind messages of support”.
William’s words of praise, delivered during a fundraising gala dinner, also recognised those who wished Kate well, as she recovers from planned abdominal surgery.
He told the guests “It means a great deal to us all.”
Kate was photographed for the first time since undergoing abdominal surgery.
Kate was pictured near Windsor Castle on Monday in the passenger seat of a car, according to TMZ.
The news site said she was wearing dark sunglasses in the black Audi which was being driven by her mother, Carole Middleton.
The photo is understood to have been taken by paparazzi.
The Army removed a claim on its website that Kate was reviewing Trooping the Colour in June.
Tickets were being sold on the official website for the June 8 military spectacle, advertising an appearance by Kate, on Tuesday evening.
Questions were raised that the first picture of the Kate to be released after her abdominal surgery may have been manipulated before it was posted on social media by Kensington Palace.
The photo of Kate and her children, said by the palace to have been taken by the Prince of Wales in Windsor earlier this week, was posted to mark Mother’s Day.
In the post, she said: “Thank you for your kind wishes and continued support over the last two months.
“Wishing everyone a Happy Mother’s Day. C.”
The picture shows Kate sitting in a chair with her arms around Princess Charlotte and Prince Louis, who are on either side of her, with Prince George standing behind, as all four smile at the camera.
The photograph was shared with media on Sunday but it was withdrawn by international picture agencies later the same day because of concerns that the image had been manipulated.
Kate publicly took the blame for the manipulated family photograph released by Kensington Palace as she issued a personal apology for the “confusion”.
Kate said sorry with a statement on social media which read: “Like many amateur photographers, I do occasionally experiment with editing.
“I wanted to express my apologies for any confusion the family photograph we shared yesterday caused.
“I hope everyone celebrating had a very happy Mother’s Day. C.”
Kate was filmed smiling alongside her husband during a visit to a farm shop in Windsor.
Kate’s recovery from surgery appeared to have progressed after footage obtained by The Sun showed her and William at the local business on Saturday.
In the video the princess can be seen with her hair down, wearing a black jacket and leggings, chatting with William and carrying a large white bag.
An investigation was reportedly launched at the London Clinic over claims staff tried to access Kate's private medical records.
At least one member of staff tried to access Kate’s notes while she was a patient at the private hospital in central London in January, The Mirror reported.
The UK privacy and data protection watchdog said it had received a breach report.
6pm – in a recorded video message broadcast to the nation, Kate announced she is having chemotherapy after tests following her surgery found cancer had been present.