Kate Middleton didn't wear her engagement ring that once belonged to Princess Diana at the Royal Marsden Hospital in London on Jan. 14. Inside why and more about Princess Kate's new ring.

The Princess of Wales wanted to “show her gratitude to the incredible team, but also highlight the world leading care and treatment the Marsden provides.”

Kate Middleton made a surprise visit to the Royal Marsden Hospital where she received cancer treatment, following her diagnosis last year.

Kate Middleton visited the Royal Marsden Hospital in London on Tuesday, Jan. 14, where she received chemotherapy treatment after her cancer diagnosis last year. See all the photos here

Catherine, Princess of Wales revealed on Tuesday that she is in remission from cancer, following a visit to the London hospital where she was treated last year.

For her first official solo appearance in over a year, Princess Kate met with cancer patients and the team at London's Royal Marsden Hospital.

The Princess of Wales made a surprise return to the Royal Marsden Hospital to personally thank staff who looked after her during her cancer treatment on Tuesday. At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.

Princess Kate reportedly made a secret visit to the Royal Marsden Hospital in London, where she previously underwent chemotherapy treatment, before Christmas. The Princess of Wales, 43, made her first solo public engagement in more than a year on January 14,

Princess Kate revealed this week that she had been a patient at the hospital last year during her cancer treatment.