Kate Middleton, Princess of Wales, revealed she is in the midst of a cancer battle and is undergoing treatment.

The 42-year-old princess and mother of three made the shocking announcement in a video released Friday, in which she described the diagnosis as a "huge shock."

"William and I have been doing everything we can to process and manage this privately for the sake of our young family," said Kate. "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's appropriate for them and to reassure them that I'm going to be okay," she added.

The revelation comes two months after Kate underwent major abdominal surgery, prompting a whirlwind of public speculation over her health. At the time, her medical team thought her condition was noncancerous, but further testing showed cancer was present, she said.

Kate did not elaborate on her specific type of cancer.

"It has been an incredibly tough couple of months for our entire family," the princess admitted.

"I'm getting stronger every day by focusing on the things that will help me heal in my mind, body, and spirits. Having William by my side is a great source of comfort and reassurance too, as is the love, support and kindness that has been shown by so many of you," said Kate.

The princess said she is in the early stages of treatment and in the process of undergoing preventative chemotherapy.

She concluded her message by asking the public for "time, space and privacy" while she completes treatment and focuses on "making a full recovery."

Earlier this year, King Charles, 75, revealed his own cancer diagnosis.