The King has been seen in public for the first time since he went to hospital after experiencing temporary side effects from his cancer treatment.
He cancelled a trip to Birmingham on Friday on medical advice after spending a short period of time in hospital on Thursday, Buckingham Palace said.
The monarch, 76, left his London residence Clarence House on Friday morning to spend the weekend privately.
His diagnosis was announced in February last year but it has not been said what type of cancer he has. The palace has not provided details on what the recent side effects were.
A palace source described it as a “most minor bump in a road that is very much heading in the right direction”.
The King was “greatly disappointed” to be missing his visit to Birmingham, the palace said in a statement on Thursday evening.
Meetings with three ambassadors were also affected, it added.
The King was said to have been “feeling good” on Thursday evening, carried out some work and shared dinner with Queen Camilla at Clarence House.
Charles returned to public duties last April after a period of treatment and recuperation.
His cancer treatment is ongoing.
