Images broadcast by British television showed how the King and his wife Camilla shook hands with people gathered on a street in York when three eggs thrown in their direction fell to the ground a few inches from where they were.
“This country was built with the blood of slaves,” shouted the author of the attack before being arrested by several agents.
“Shame on you!” shouted some of the hundreds of admirers who had come to greet the new royal couple. “God save the King,” others added.
Charles III, 73, and the queen consort, 75, were visiting northern England, where a statue of Queen Elizabeth II was due to be unveiled on Wednesday, the first since the iconic monarch’s death in September.
The king, who will be officially crowned at a ceremony in MayEight months after ascending the throne, he is far less popular than his late mother, admired by the British during her 70-year reign.
However, after the death of Isabel II, Carlos III saw his popularity increase, although he is still less appreciated than his son Guillermo, heir to the throne, and his wife, Catalina.