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.

Smiling and waving, King Charles III left his home in London the day after a brief hospitalization for the side effects from his cancer treatment. Buckingham Palace announced that the monarch's engagements for the day were scrapped following a "short period of observation in hospital" on Thursday.

After a brief hospital stay due to side effects from his cancer treatment, King Charles III has been discharged.