Despite or maybe because of his fiery attitude, Prince Philip did much to popularise polo in the 1950s and 1960s. He founded the Household Brigade Polo Club (later the Guards Polo Club) in 1955, which has ten polo pitches on Smith’s Lawn in Windsor Great Park where the Queen is often a spectator. She breeds polo ponies along with her thoroughbred racehorses. Philip also promoted bicycle polo, which enabled those who couldn’t afford the real thing to get a taste of polo without all the expense. It is now a firmly established sport with international competitions.

However, polo is not an old man’s game, and in 1971 Prince Philip gave it up in favour of carriage driving, which involves driving a four-in-hand around an obstacle course against the clock. Philip became so involved with the sport that he revised the rules of competitive carriage driving and wrote on a book on it: 30 Years on and Off the Box Seat. With his penchant for invention, he redesigned various wooden parts of the carriage that were inclined to break and replaced them with metal ones. Philip’s competitive spirit was always seen at the annual Royal Windsor Horse Show. He was still driving at the age of ninety-five, no longer in competitions but going out with his carriage and team of Fell ponies in all weathers.

Unsurprisingly, the Queen and Prince Philip’s children and grandchildren have competed in equestrian events with great success, most notably Princess Anne and Zara Phillips. In an essay on horses, he wrote: ‘Having a family which seems to be equally willing to be humiliated by the horse, I have to live with the expectation that they too will suffer injury and indignity . . . I am not surprised when it happens to them and I am full of sympathy and useful advice for treatment and recovery.’

However, there are other sports that have had the royal seal of approval. Sailing is an important part of the curriculum at Gordonstoun and was something at which young Philip excelled. His sailing days may be over, but he is still a regular presence at Cowes Week as admiral of the Royal Yacht Squadron, one of the most prestigious yacht clubs in the world, with the Queen as their patron.

Despite this, sailing is a sport where Philip tends to operate separately from the Queen. At Cowes, he would spend his time with Uffa Fox, not his wife. Fox was a boat designer and builder by trade, but also a raconteur, bon vivant and all-round eccentric individual. Prince Philip wrote the foreword to Uffa’s biography, including these words: ‘His life was one long campaign for the freedom of the human spirit and against the foolish, the stupid and the self-important, the whole conducted with a cheerful breeziness that disarmed all but the hardest of cases.’