King Charles was admitted to hospital on Thursday to be treated for side effects from his planned cancer treatment and has been forced to cancel engagements, Buckingham Palace said late last night. Charles, 76, was admitted to the London Clinic yesterday afternoon and is now back home at Clarence House.

As a precautionary measure, the monarch has cancelled his planned away day to Birmingham today where he was due to conduct a busy schedule of engagements. A source described it as a "most minor bump in a road that is very much heading in the right direction".

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".

The King was diagnosed with an undisclosed form of cancer last February and continued to undergo weekly treatment.

He postponed public-facing duties for just under 12 weeks before resuming a normal diary of engagements, including a gruelling tour of Australia and Samoa.

His planned state visit to Italy at the start of April is still expected to go ahead. Charles and Camilla are due to arrive in Rome on Monday, April 7, and will conduct a busy four-day programme of engagements.

The King has conducted a flurry of engagements this year, travelling up and down the country and last week he spent three days in Northern Ireland with the Queen.

This week, he hosted an Investiture Ceremony at Windsor Castle, attended two evening receptions, visited an exhibition and conducted audiences.

His diary is expected to continue as normal next week, though decisions may be taken at the last minute to protect and prioritise the King's continued recovery.

A royal source says the King is on good form at home, working on state papers and making calls from his study.

A Buckingham Palace spokesperson said: "His Majesty was due to receive credentials from the ambassadors of three different nations this afternoon.

"Tomorrow, he was due to undertake four public engagements in Birmingham, and is greatly disappointed to be missing them on this occasion.

"He very much hopes that they can rescheduled in due course and offers his deepest apologies to all those who had worked so hard to make the planned visit possible."

The King travelled to and from the London Clinic - the private hospital where he was treated for an enlarged prostate in January 2024 and where the Princess of Wales spent 13 days recovering from major abdominal surgery - by car.

He was not joined by the Queen, who conducted a planned solo engagement yesterday, during his brief stay.

It is understood the side effects, of which specifics have not been disclosed, were temporary and not uncommon with many medical treatments.

A palace source said the King's "recovery path continues in a positive direction" and insisted that the brief hospital admission was "no drama".

But the news is a sobering reminder that the monarch, who is determined to keep up a normal schedule of engagements, continues to be treated for cancer.

Yesterday's announcement continues the King's determination to be as open as possible about his diagnosis while retaining medical privacy.

Buckingham Palace implied that they would not be issuing any further updates as this was "not a major development" but will advice if any further tweaks to his diary will need to be made.

It is understood that the late-night announcement was because his medical team was working with his staff to decide whether the Birmingham trip should go ahead.

But the decision was made to postpone to safeguard the King's recovery.

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."