THE PRINCESS of Wales has cancer and is undergoing preventative chemotherapy.
Catherine said in a video message it was a ‘huge shock’ after an incredibly tough couple of months but said she is ‘getting stronger every day’.
Kensington Palace says it is confident the princess will make a full recovery.
The princess said in January she underwent major abdominal surgery in January.
She said: "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.”
Catherine said recovery from her surgery had taken time and the priority was now her family.
"William and I have been doing everything we can to process and manage this privately for the sake of our young family."
The princess added: "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 okay."
She said the family now needs "some time, space and privacy".
Born Catherine Elizabeth Middleton, she married Prince William, The Prince of Wales, at Westminster Abbey on 29 April 2011.
The couple have have three children, Prince George, Princess Charlotte and Prince Louis.
The family's official residence is Kensington Palace.
Catherine holds patronage with over 20 charitable and military organisations including the Anna Freud Centre, Action for Children, SportsAid, and the National Portrait Gallery.
In January Buckingham Palace announced that the Princess had been admitted to hospital for planned abdominal surgery.
They said it was successful and it was expected she would remain in hospital for ten to fourteen days, before returning home to continue her recovery.
Reacting to the announcement, Wales’ First Minister, Vaughan Gething said: “Deeply saddened to hear the news about HRH The Princess of Wales.
“On behalf of people across Wales, I would like to send our love and support to the Princess and her family at this very difficult time. “All of our thoughts are with you as you continue your treatment.”