Kate Middleton says she was diagnosed with cancer, is undergoing chemotherapy

Catherine, Princess of Wales, was diagnosed with cancer and is undergoing chemotherapy, she said in a video message released on Friday.

The type of cancer has not been disclosed. She started chemotherapy in late February and the announcement comes as her father-in-law, King Charles, also undergoes cancer treatment.

"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," Kate, 42, said in the video, which was filmed at Windsor on Wednesday. "As you can imagine, this has taken time. It has taken me time to recover from major surgery in order to start my treatment."