William signed the post with his initial, \"W,\" indicating he wrote the message himself. The post also included a photo of Kate that was taken by photographer Matt Porteous over the summer in Windsor, according to Kensington Palace.

On her birthday last year, Kate was one week away from being admitted to a London hospital, where she would undergo what Kensington Palace described at the time as \"planned abdominal surgery.\"

\"PHOTO:
Samir Hussein/WireImage/Getty Images
PHOTO: Catherine, Princess of Wales attends the Christmas Morning Service at Sandringham Church, Dec. 25, 2024, in Sandringham, England.
>

Kate spent nearly two weeks hospitalized before being discharged in late January.

After her hospitalization, Kate took extended time off from her public royal duties, leading to a frenzy of speculation online about her well-being and whereabouts.

Amid the speculation about her health, Kate issued a public apology over a photo of herself with her kids that was shared on social media for Mother's Day and later revealed to be edited. In her apology, Kate apologized for any \"confusion\" those alterations caused.

Less than two weeks later, on March 22, Kate revealed in a video message that she had been diagnosed with cancer.

\"In January, I underwent major abdominal surgery in London and at the time, it was thought that my condition was non-cancerous. The surgery was successful,\" Kate said in the video message. \"However, 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.\"

Kate has not shared the type of cancer she was diagnosed with nor the details of her treatment.

She remained out of the public spotlight for several more weeks following her announcement, before joining the royal family in May at Trooping the Colour.

\"PHOTO:
Chris Jackson/Getty Images
PHOTO: Prince George of Wales, Prince William, Prince of Wales, Prince Louis of Wales, Catherine, Princess of Wales and Princess Charlotte of Wales on the balcony during Trooping the Colour at Buckingham Palace, June 15, 2024, in London.
>

In September, Kate announced that she had finished chemotherapy and was focused on staying \"cancer free\" and gradually returning to work.

In the following months, Kate made several public appearances, including traveling to Southport, England, with William and hosting her annual Christmas carol service at Westminster Abbey.

Kate's last public appearance before her birthday was on Christmas morning.

\"PHOTO:
Samir Hussein/WireImage/Getty Images
PHOTO: Prince William, Prince of Wales, Prince Louis of Wales, Prince George of Wales, Catherine, Princess of Wales and Princess Charlotte of Wales attend the Christmas Morning Service at Sandringham Church, Dec. 25, 2024, in Sandringham, England.
>

She joined William, as well as Charlotte, George, Louis and other royal family members, as they walked to church at Sandringham on Christmas morning, following royal tradition.

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