LONDON - The Princess of Wales is undergoing treatment for cancer, she has announced in a personal video message, but told the world: “I am going to be ok.”

The Princess is undergoing a course of preventative chemotherapy and has said she is focused on making a “full recovery”.

The cancer was identified during tests after her abdominal surgery on Jan 16, and she began treatment in late February.

Since then, she and the Prince have been focusing on sharing the news with their three young children and allowing the family to process it in private.

The Princess has now chosen to share the diagnosis in a video message filmed at Windsor on Wednesday, in which she thanked the public for their support and shared her “huge shock” at the news.

In recent weeks, she and the Prince of Wales have been subjected to worldwide conspiracy theories about her health and whereabouts.

She said the Prince had been a “great source of comfort and reassurance” as she has come to terms with her diagnosis.

The couple chose to announce it on Wednesday after Prince George, Princess Charlotte and Prince Louis broke up for their school Easter holidays and could be sheltered from the public reaction at home.

The Princess said it had taken her and the Prince “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”.

In her message she said: “As I have said to them, I am well and getting stronger every day by focusing on the things that will help me heal in my mind, body and spirits.”

The Princess received her diagnosis in late February. It is the reason the Prince of Wales missed the memorial for his godfather on Feb 27.

Addressing the public in the video, filmed by BBC Studios, the Princess said: “I wanted to take this opportunity to say thank you personally for all the wonderful messages of support and for your understanding whilst I have been recovering from surgery.

“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.

“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. 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.”

The Princess is now said to be on a “recovery pathway”. Kensington Palace is not sharing the type of cancer, or the stage at which it was found, citing the Princess’s right to medical privacy.

Speaking on the video, which was released by the Palace directly for the public to see on its social media, the Princess said of the news: “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.

“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.

“As I have said to them, I am well and 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. It means so much to us both.”

In a renewed plea for privacy, and a message of hope for others who are also facing cancer treatment, the Princess added: “We hope that you will understand that, as a family, we now need some time, space and privacy while I complete my treatment.

“My work has always brought me a deep sense of joy and I look forward to being back when I am able, but for now I must focus on making a full recovery.

“At this time, I am also thinking of all those whose lives have been affected by cancer. For everyone facing this disease, in whatever form, please do not lose faith or hope. You are not alone.”

The Princess has been away from public duties since Christmas Day, when she was seen walking to Sandringham church with her family.

She was admitted to the London Clinic on Jan 16, with the Palace issuing a statement the next day to confirm that she would be in hospital for up to two weeks and recovering in private until after Easter.

At the time, it was specified that the condition was non-cancerous and that the operation had been a success.

It was only in post-operative tests that cancer was identified. She began preventative chemotherapy in late February.

A spokesman for Kensington Palace said: “The Princess is now on a recovery pathway having commenced a course of preventative chemotherapy.”

He added that the Princess had wanted to share this information “when she and the Prince felt it was right for them as a family”.

The family will not be attending church at Easter. The Princess will return to official duties when she has clearance from her medical team. The Prince will be back to a schedule of public engagements in mid-April, after the Easter holiday.

A spokesman for Kensington Palace said: “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 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.”

Asked for further details about the condition or operation, the spokesman said: “We will not be sharing any further private medical information. The Princess has a right to medical privacy, as we all do.”

The Princess’s cancer diagnosis follows that of the King. His diagnosis was also made in post-operative tests, and confirmed in a public statement on Feb 6. He had had a procedure for the symptoms of an enlarged prostate.

The King and Queen are aware of the Princess’s diagnosis, and that she was releasing a message to the public.