His difficulties at the school did not prevent him becoming Guardian, as Gordonstoun’s head boy is called, as his father had been. The whole point of Charles’s education, as Prince Philip saw it, was to train him to accept responsibility, a responsibility that was his by birthright and one which was not to be evaded.

For Charles, there was no escaping his destiny. ‘I didn’t suddenly wake up in my pram one day and say, “Yippee,” ’ he said, referring to the prospect of his kingship. ‘It just dawns on you slowly that people are interested . . . and slowly you get the idea that you have a certain duty and responsibility. It’s one of those things you grow up in.’

He was surrounded by reminders of who he was and what lay ahead. His mother’s face was on the stamps he stuck on the letters to Mispy and on the coins he bought his chocolate with in his schools’ tuckshops – a fact that his schoolmates were not slow to point out. Brought up among the sons of the privileged, he was always more privileged, and a personal protection officer accompanied him to Gordonstoun. Whereas everyone else had to see each term at Gordonstoun through without the benefit of a break (there was no half-term holiday at the school when he was there), he was allowed out to join his parents on various state occasions.

He was spared the anxiety of choosing a career – he was going to Cambridge. Then, and despite his seasickness, he was going into the navy. Everything was laid out for him. His great uncle, Earl Mountbatten, spelt it out: ‘Trinity College like his grandfather; Dartmouth like his father and grandfather; and then to sea in the Royal Navy, ending up with a command of his own.’ A suitable marriage would follow. In 1987, in a cry of frustration, he declared: ‘You can’t understand what it’s like to have your whole life mapped out for you a year in advance. It’s so awful to be programmed. I know what I’ll be doing next week, next month, even next year. At times I get so fed up with the whole idea.’

As a youth he had to bear it even if he couldn’t grin. And no matter how definite the plan, it provided no protection against the bruisings he received along the way. Rather the contrary. When he was at Cheam, he watched his mother on television announce that she was going to make him Prince of Wales. ‘I remember being acutely embarrassed,’ he recalled. ‘I think for a little boy of nine it was rather bewildering. All the others turned and looked at me in amazement.’