Kate Middleton's cancer diagnosis came as a "huge shock" to the royal, as well as the rest of the world.
The Princess of Wales revealed she is undergoing preventative chemotherapy in a personal video message shared on March 22. The news came after weeks of speculation regarding Kate's health following her "planned abdominal surgery" in January.
"In January, I underwent major abdominal surgery in London, and at the time, it was thought that my condition was non-cancerous," she said in the emotional video, sharing that after she underwent tests following the surgery, it was determined that "cancer had been present."
A Complete Timeline of Kate Middleton's Abdominal Surgery and Cancer Diagnosis
Prior to her announcement, Princess Kate had largely remained out of the public eye, though she and Prince William were filmed by a local resident whileshopping in Windsor. The princess shared in her video that she and William were managing her health privately "for the sake of [their] young family" as they tried to find an "appropriate" way to tell their children, Prince George,Princess Charlotte andPrince Louis.
“It has been an incredibly tough couple of months for our entire family, but I’ve had a fantastic medical team who have taken great care of me, for which I am so grateful," she said in her video.
In June 2024, Kate was seen for the first time since her diagnosis in a new photo of herself in the woods of her home, accompanied by a personal letter.
"I have been blown away by all the kind messages of support and encouragement over the last couple of months," she wrote. "It really has made the world of difference to William and me and has helped us both through some of the harder times."
At the end of that summer, in September 2024, Kate announced had completed chemotherapy.
From how Prince William and the royal family have been supporting her to when she might return to royal duty, here's everything we know so far about Kate Middleton's cancer diagnosis and treatment.
Kate’s condition was thought to be non-cancerous when she underwent major abdominal surgery
When Kate underwent "major abdominal surgery" in January, doctors originally believed her condition to be non-cancerous.
Kate received her surgery at The London Clinic, where she stayed for 13 days during her recovery. Upon her release, the palace issued a statement with an update that she was "making good progress."
“The Princess of Wales has returned home to Windsor to continue her recovery from surgery. She is making good progress," Kensington Palace said in a statement. “The Prince and Princess wish to say a huge thank you to the entire team at The London Clinic, especially the dedicated nursing staff, for the care they have provided."
She was diagnosed with cancer following tests after her surgery
Though the abdominal surgery was successful, Kate underwent tests after the operation, during which doctors discovered that "cancer had been present."
Around the same time, on Feb. 5, the palace announced that King Charles was diagnosed with cancer following treatment for a benign prostate enlargement.
"His Majesty has today commenced a schedule of regular treatments, during which time he has been advised by doctors to postpone public-facing duties. Throughout this period, His Majesty will continue to undertake State business and official paperwork as usual," the statement said.
King Charles and Queen Camilla were subsequently informed of Kate's cancer news.
Kate did not specify which type of cancer she has been diagnosed with in her video.
Following her announcement, a Kensington Palace spokesperson said, "We will not be sharing any further private medical information. The Princess has a right to medical privacy, as we all do."
Kate is in the early stages of preventative chemotherapy
Following her diagnosis, Kate was advised to begin chemotherapy, she explained.
“Tests after the operation found cancer had been present. My medical team therefore advised that I should undergo a course of preventative chemotherapy and I am now in the early stages of that treatment," she said.
The princess did not, however, elaborate on when started her treatment or how long it is expected to last.
She and William took time to find the “appropriate” way to inform their children
The Princess of Wales shared that it was important to her to take the time not only to process the diagnosis, which came as a "huge shock," but also to explain the situation to her three children: George, Charlotte and Louis.
Prince William and Kate Middleton's 3 Kids: All About George, Charlotte and Louis
“This of course came as a huge shock, and William and I have been doing everything we can to process and manage this privately for the sake of our young family," she said. "As you can imagine, this has taken time. It has taken me time to recover from major surgery in order to start my treatment."
"But, most importantly, it has taken us time to explain everything to George, Charlotte and Louis in a way that is appropriate for them, and to reassure them that I am going to be ok," she added.
The princess may have strategically waited until the children were off from school to make her announcement. George, Charlotte and Louis all attend the Lambrook School, which was on a half-term break, giving the familyprivate time together following Princess Kate's announcement.
William has been a “great source of comfort” to Kate
Following the news of Princess Kate's planned surgery back in January, PEOPLE reported that William was expected to postpone some engagementsto be by Kate’s side. The following day, he was photographed driving himself to visit Kate at the hospital.
The prince continues to support the princess amid her cancer treatment, as Kate reiterated in her video message.
“Having William by my side is a great source of comfort and reassurance too," she said. "As is the love, support and kindness that has been shown by so many of you. It means so much to us both."
A Kensington Palace spokesperson confirmed to PEOPLE that following Kate's cancer diagnosis announcement, Prince William will continue official duties while balancing his work responsibilities and family life.
"The Prince will continue to balance supporting his wife and family and maintaining his official duties as he has done since the start of the year," the spokesperson said.
In May 2024, one of the royals' go-to designers, Amaia Arrieta told The Telegraph that she was concerned for the royal couple as they dealt with Kate's diagnosis.
"I'm heartbroken at the moment. I think they are going through hell," she said. "I hope they will be back. It's really personal."
King Charles is “so proud” of Kate’s honesty
As King Charles undergoes treatment for his own diagnosis, he is "so proud of Catherine for her courage in speaking as she did," a Buckingham Palace spokesperson told PEOPLE.
Both the monarch and Kate were hospitalized at The London Clinic in January and Charles has "remained in the closest contact with his beloved daughter-in-law throughout the past weeks," the spokesperson added.
He and Queen Camilla “will continue to offer their love and support to the whole family through this difficult time."
It is unknown when Kate will return to royal duty
Although Kensington Palace initially announced after Kate's surgery that she was expected to return to royal duties after Easter, it remains unclear when she'll return following her cancer diagnosis.
According to a palace spokesperson, the princess will make her official return based on advice from her doctors as she undergoes chemotherapy.
"The Princess will return to official duties when she is cleared to do so by her medical team. She is in good spirits and is focused on making a full recovery," the spokesperson told PEOPLE.
While she still had not returned to royal duties, Kate did step out in May 2024 to run errands solo and was seen out with her family, sources told PEOPLE. However, she continues to not return to work until she is given the all-clear by her medical team.
In June 2024, she announced that she would be joining her family at the annual Trooping the Colour event in honor of King Charles' birthday. The event would mark her first public appearance with the royal family since Christmas.
"I'm looking forward to attending the King’s Birthday Parade this weekend with my family and hope to join a few public engagements over the summer, but equally knowing I am not out of the woods yet," she said.
Kate was seen for the first time since her announcement in a June 2024 photo
Three months after her cancer diagnosis announcement, Kate released the first photo of herself in the royal outdoors in Windsor where she lives with William and their kids. She was dressed casually, in a blazer and jeans with her arms folded.
She also wrote an accompanying letter, where she gave well-wishers an update on her progress.
"I am making good progress, but as anyone going through chemotherapy will know, there are good days and bad days. On those bad days, you feel weak, tired and you have to give in to your body resting. But on the good days, when you feel stronger, you want to make the most of feeling well," she wrote.
Kate continued, "On the days I feel well enough, it is a joy to engage with school life, spend personal time on the things that give me energy and positivity, as well as starting to do a little work from home."
Kate concluded her chemotherapy treatment in September 2024
In September 2024, Kate announced that she had finished chemotherapy after months of treatment.
"As the summer comes to an end, I cannot tell you what a relief it is to have finally completed my chemotherapy treatment," Kate said in a video filmed near her family's home in Norfolk in August 2024. "The last nine months have been incredibly tough for us as a family. Life as you know it can change in an instant and we have had to find a way to navigate the stormy waters and road unknown.
She added that the cancer journey reminded her and Prince William to "be grateful for the simple yet important things in life," and that she looked forward to returning to public engagements and working.
"I am however looking forward to being back at work and undertaking a few more public engagements in the coming months when I can," she said. "Despite all that has gone before, I enter this new phase of recovery with a renewed sense of hope and appreciation of life."