The 76 -year -old “required a short observation period at the Hospital” Thursday morning, said the Palace.
His afternoon commitments postponed “as a precautionary measure” and “acting on medical advice.”
Since then, King Charles has returned to Clarence House, his residence in London.
The Palacio’s full statement, sent on Friday morning in Australia, says: “After a scheduled and continuous medical treatment for cancer this morning, the king experienced temporal side effects that required a short period of observation in the hospital. Therefore, his Majesty commitments postponed.
“His Majesty has now returned to Clarence House and, as a precautionary measure, acting on medical advice, tomorrow’s daily program will also be reprogrammed.
“His Majesty would like to send their apologies to all those who may be annoying or disappointed as a result.”
Buckingham Palace has not revealed the nature of the king’s treatment.
In April of last year, the monarch returned to the public’s tasks after a prolonged period of his medical team.
This is a last minute story, more to come.