“He knows how to work a crowd – and he has been preparing for this job as king for decades.”

The royal historian added: “Charles is far less formal than his mother.

“I do not think the late Queen would have stopped at that food truck. Prince Philip might have, however.”

Commenting on the King’s speech, during which he spoke about Britain’s “abhorrent and unjustifiable acts of violence committed against Kenyans” but failed to apologise, Koenig noted that there’s only so much Charles can say or do as monarch.

She explained: “His speech at the state banquet would have been vetted and advised by the government, on what he could and could not say.

“He must avoid controversy – and it would be the government to provide an apology.

“The implications of the King speaking on his own would or could contribute to a constitutional crisis.

“When he was Prince of Wales, he spoke out about the injustices of British colonialism, but now he must be careful about the words he uses.”

Meanwhile, the royal historian praised Queen Camilla who, unlike the late Queen, is undertaking engagements that “might make some people squirm”.

She said: “Queen Camilla is undertaking engagements that are aligned with her own interests. She has been a long-time advocate for sexual abuse victims – and has continued this in Kenya by meeting with sexual abuse victims.

“For the [late] Queen, it would have been tea with a group of ladies. But that was the past.

“Queen Camilla is not afraid to take on engagements that might make some people squirm. Supporting and meeting with sexual abuse victims is a powerful statement.”