James Edwards, his former headmaster, received a letter from the prince two days after his resignation. ‘It was a long letter thanking me for my concern and explaining why he had done what he had done. He said Prince Philip had been extremely supportive and because of that, he felt he could make the right decision. I think he had had a rough time and had been bullied and teased about gayness until he couldn’t take it any more. Physically he did not have a problem as he was very tough despite his angelic looks.’ Edwards explained that the prince’s detective Andrew Merrylees was away on a recce of New Zealand at the time and perhaps if he had been around Edward might have stuck it out at least until the end of his course.

Prince Philip and the Queen may not always agree, and clearly did not in this case, but as James Edwards said: ‘They are a tight unit. Cross one and you’ve crossed them both.’

For all their superficial differences, Philip had a better relationship with Prince Edward than with Charles or Andrew, based on respect on Edward’s part and equally genuine affection on Philip’s. He is not a demonstrative man, but in private he will affectionately put his arm around his son’s shoulder – he calls him Ed – and give him a kiss. Before his marriage in 1999, Edward always kept one book on his bedside table at Buckingham Palace. It was his journal of the Duke of Edinburgh’s Award, its handwritten pages bearing testimony to the years he spent achieving his three awards. The book is a diary of his youth, written in many different hands by those who taught him and those he came to respect. It is a symbolic reminder of the empathy between the prince and his father, whose name the scheme bears.

Indeed, his father and the award have been two of the most notable influences in his life. It was Philip, for instance, not the Queen, who came to see Edward receive his degree on graduation day from Cambridge. ‘Prince Philip can freeze or melt an atmosphere depending on his mood,’ says friend and former director of the Duke of Edinburgh’s Award, Sir Michael Hobbs. ‘If he is irritable or unhappy about something he will make no attempt to hide it.’

‘Prince Philip’s attitude to life was formed by a very tough upbringing,’ observed Hobbs. ‘He meets discomfort head on and isn’t worried by it. He is much less overtly compassionate as a result. He keeps it well hidden.’

Like the duke on a good day, Edward can move smoothly through a room, sipping a drink, smiling at the appropriate moment, making a humorous remark, before seamlessly moving on. It is an acquired skill, one that did not come easily, and is something the Queen has always found difficult.