King Charles has been forced to cancel several royal engagements after the monarch underwent a secret and "brief" visit to hospital.
The 76-year-old had been due to hold engagements on Thursday afternoon and to visit Birmingham on Friday, but he has now cancelled the trip in order to focus on his recovery following his cancer diagnosis last year. HELLO! understands that the King has returned to his London home of Clarence House and will be working from there.
HELLO! also understands that the King's recovery from his illness is progressing as expected and that incidents like this are expected. A source described it as a "minor bump in the road".
A statement from Buckingham Palace read: "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."
A spokesperson added: "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 apologiesto all those who had worked so hard to make the planned visit possible."
Despite this postponement, it's expected that the King and Queen Camilla will still undertake their state visit to Italy next month. There has already been a change to the monarch's itinerary on the trip as he is no longer due to meet Pope Francis owing to the pontiff's recent hospital stay.
Pope Francis, 88, was discharged from Rome's Gemelli hospital last week after being admitted on 14 February after experiencing breathing difficulties. He was first treated for bronchitis after being diagnosed with pneumonia in both lungs.
According to the BBC, doctors have said he will need at least two months of rest at the Vatican.
During a trip to Northern Ireland last week, Charles spoke to people living with cancer, and asked whether they were managing to "survive the side effects alright?" before adding sympathetically: "You just have to push on, don't you?"
While the comments are rare, Buckingham Palace sources told Sky News in December last year that "his treatment has been moving in a positive direction and as a managed condition the treatment cycle will continue into next year".
The Palace has still not disclosed the type of cancer Charles has, with a palace source revealing to The Times that this is a conscious choice in order for the King to reach out to the widest number of people who are experiencing the disease, rather than narrow the focus onto a particular form of cancer.