King Charles has been diagnosed with cancer, Buckingham Palace has said.
It is not prostate cancer, but was discovered during his recent treatment for an enlarged prostate.
The type of cancer has not been revealed, but according to a Palace statement the King began "regular treatments" on Monday.
The King, 75, will step back from his public engagements and Queen Camilla and Prince William will help to stand in for him during his treatment.
No further details are being shared on the stage of cancer or a prognosis.