Hats are important. You only have to look at old photographs – say, of visitors to the Chelsea Flower Show in the 1930s: everybody in hats, men and women. Before the war, my grandmother spied Nancy Astor’s daughter in Bond Street without a hat. She agonised over whether to inform Lady Astor of this outrage. Yet when I encountered Drusilla Beyfus, great Vogue authority, in the green room before a radio show, she insisted that hats had never been a social obligation, merely a fashion. I don’t think hats were a fashion, though they were certainly subject to fashion.

You might assume that hat-wearing is now a thing of the past, but Drake Stutesman insists not. Look at the baseball cap or the beanie. But what is a hat and what is it for? One thing we can be sure of is that hats are not garments in the usual sense of the word. Only intermittently are they essential for warmth, keeping dry or cool. Quite often nowadays, hat wearers at weddings are keen to remove them as soon as possible. Hats are not comfortable. In most places today, they are not required for a person to meet society’s expectations of being dressed.

So is a hat merely decorative, an idle accessory? It would seem not, though women’s hats even today are almost always trimmed with ribbons, artificial flowers or feathers. We don’t think it odd that the Queen, champion and nearly lone hat wearer for the last fifty years, should appear at