Even though it is a very important occasion, the food served will be light. The Queen is aware that there will be a state banquet that night, and that her guests will have a busy schedule that afternoon. No one lingers over the meal. By three o’clock the entire party is back in the 1844 Room for coffee and liqueurs and the ceremony of exchanging presents takes place. The presents that the Queen is given vary from lavish ones, particularly if they are from an Eastern country, down to something as simple as a small piece of furniture. In return, the guests are invariably given a silver salver and a signed photograph in a leather frame of Her Majesty and the Duke of Edinburgh, which the household nickname ‘the glums’. Honours are also exchanged after this lunch. Some guests are given honorary knighthoods, and the Queen may be given the highest rank available in her visitor’s country. That evening, at the glittering state banquet, the Queen and her visitor will wear the sash of their newly acquired honour.

But these grand occasions are few and far between. The luncheon hour is not normally a time when anything much happens in the royal life. When the Queen is at work, she almost always lunches alone in her private dining room on the first floor. All she eats is a main course and salad, followed by coffee, brought in by her footman. And she usually serves herself from the hotplate that is left permanently in her dining room.

On the rare occasions when she and Prince Philip lunch on their own together, the duke likes to choose something new and different from the chef’s suggestions, or something he may have sampled on one of his frequent evening engagements. Even until his ninety-sixth year, he was still attending official dinners, which he enjoyed, despite the huge amount of energy he had to muster to do so. When the royal couple are alone, they often have what they call an ‘experiment lunch’. They would never dream of giving guests something they had not eaten themselves. As the duke still takes a great interest in food, it is usually him not the Queen who will write any alterations or suggestions in the menu book.