King Charles spent time in hospital on Thursday (27.03.25) after experiencing "temporary side effects" during his cancer treatment

Buckingham Palace said in a statement: "Following scheduled and ongoing medical treatment for cancer this morning, The King experienced temporary side effects that required a short period of observation in hospital. His Majesty's afternoon engagements were therefore postponed.

"His Majesty has now returned to Clarence House and as a precautionary measure, acting on medical advice, tomorrow's diary programme will also be rescheduled.

"His Majesty would like to send his apologies to all those who may be inconvenienced or disappointed as a result."

Buckingham Palace announced news of the King's diagnosis in February 2024.

The monarch underwent a "corrective procedure" for an enlarged prostate and doctors noticed a "separate issue of concern" that led to his cancer diagnosis.

The Palace said at the time: "During The King's recent hospital procedure for benign prostate enlargement, a separate issue of concern was noted. Subsequent diagnostic tests have identified a form of cancer.

"His Majesty has today commenced a schedule of regular treatments, during which time he has been advised by doctors to postpone public-facing duties. Throughout this period, His Majesty will continue to undertake State business and official paperwork as usual.

"The King is grateful to his medical team for their swift intervention, which was made possible thanks to his recent hospital procedure."

Charles - who ascended to the throne in 2022, following the death of Queen Elizabeth - was said to be feeling "positive about his treatment".

The statement continued: "He remains wholly positive about his treatment and looks forward to returning to full public duty as soon as possible.

"His Majesty has chosen to share his diagnosis to prevent speculation and in the hope it may assist public understanding for all those around the world who are affected by cancer."

Charles underwent treatment for an enlarged prostate in late January 2024.

The Palace said in a statement at the time: "The King was this afternoon discharged from hospital following planned medical treatment and has rescheduled forthcoming public engagements to allow for a period of private recuperation.

"He would like to thank the medical team and all those involved in supporting his hospital visit, and is grateful for all the kind messages he has received in recent days."