For some reason you don’t expect people to be fans of the Mitford sisters, as others are fans of Doctor Who or Justin Bieber. But just in case this subset of humanity does exist, we have The Mitford Girls’ Guide to Life (The History Press, £12.99). Lyndsy Spence’s elegant little hardback is a compendium of all things Mitford, from family nicknames (‘Sir Ogre’ for Sir Oswald Mosley) and fashion tips (tweed skirts only on weekdays) to Pamela’s household hints (‘choose an aga to match one’s eyes’) and Diana’s guide to prison life (take a fur coat to use as a blanket, use congealed hot chocolate as face cream).

True Mitford fans probably know all this stuff anyway, but for the rest of us it’s upper-class British eccentricity distilled to its essence, like Camp coffee, except possibly camper. Ms Spence doesn’t quite speak the language — she uses non-U words like ‘gift’, and seems to believe that the piece of white cotton once spread over the backs of chairs to mop up hair oil was an ‘anti-massacre’ — but this crazed and wilfully inconsequential book, clearly a labour of love, is touched with genius. Somehow we need to know that Unity recorded in her diary each of the 140 occasions she met Hitler, and that when Nancy unwrapped her Christmas present from Diana and, without a second glance, threw it in the fire, Diana was ‘grateful for her honesty’. Bonkers? We shall not look upon their like again.