Charles took part in 372 public engagements last year, even after stepping aside for almost three months because of cancer treatment, according to data compiled by The Times of London newspaper. That made him the second-busiest royal behind his sister, Princes Anne, who had 474 engagements.

It was not the week’s end that King Charles, 76, was anticipating—the monarch was unexpectedly hospitalized on Thursday due to side effects from his cancer treatment. He was quickly released, with a royal source saying that this was “the most minor bump in the road that’s very much heading in the right direction,

King Charles III was briefly hospitalized Thursday amid ongoing medical treatment for cancer, according to Buckingham Palace. Charles' hospitalization was a result of "temporary side effects" he experienced after undergoing what the palace described as "scheduled and ongoing medical treatment for cancer" on Thursday morning.

The announcement from Buckingham Palace that King Charles had been in hospital after experiencing side effects from his cancer treatment came hours before he was due to visit Birmingham on Friday. The official statement was released at 21:00 GMT on Thursday.

King Charles III waved to well-wishers in central London on Friday as he headed for his country estate in western England a day after he was briefly hospitalized because of side effects from a scheduled cancer treatment.

King Charles waved to well-wishers as he left his London residence one day after a health setback. The British monarch, 76, was photographed being driven away from Clarence House on March 28, the day after he was briefly hospitalized for a negative reaction to his routine cancer treatment.

King Charles 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,

The news from Buckingham palace was shocking. Over a year after King Charles had announced that he had been diagnosed with cancer, the Palace issued a statement saying the King had experienced side effects from his treatment that were sufficiently severe to warrant observation in hospital.

King Charles' appointments were canceled after his "short period of observation in hospital," Buckingham Palace said.