King Charles III spent a short period of time in hospital on Thursday after experiencing temporary side effects during cancer treatment, Buckingham Palace said.

The King returned to Clarence House, where he was said to be continuing to work on state papers and make calls from his study. He has cancelled a tour of Birmingham on Friday, acting on medical advice.

Charles, 76, had planned to travel to the city for a busy schedule of engagements, which included four events.

The palace first announced the King’s cancer diagnosis in February 2024.

A Buckingham Palace spokesperson said meetings with three ambassadors on Thursday were also affected.

“Tomorrow, he was due to undertake four public engagements in Birmingham and is greatly disappointed to be missing them on this occasion,” the palace’s statement added.

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

A palace source described it as a “most minor bump in a road that is very much heading in the right direction”.

The palace did not provide further information over what his side effects were.

It comes after the King and Queen Camilla postponed their state visit to the Vatican earlier this week, following Pope Francis’s recent illness.

The wider state visit to Italy is set to continue in April with some alterations to the planned programme, the palace said this week.

The announcement from the palace was made late on Thursday because time was required for the King to consult his staff and medical team on his return to Clarence House.

The palace has never disclosed what type of cancer the King has. He returned to public duties last April after a period of treatment and recuperation.