Few siblings have enthralled Britain as supremely as the six Mitford Sisters. Their lives were stranger than fiction: Unity became sexually obsessed with Hitler and shot herself in the head at the outbreak of WWII. Diana ran off with Fascist leader Oswald Mosley and was imprisoned, while Decca joined the Communists and fled to the Spanish civil war. The best-known of the six must be the novelist Nancy, the eldest sister, who was at the vanguard of the hard-drinking Bright Young People of the '20s and '30s. Nancy was anti-Fascist but staunchly pro-Aristocracy, promoting upper class English usage (U) over middle class terms (non-U).

And then we have Deborah, the youngest, quietest of all, who preferred country life to the rabid adventures of her town-mice sisters. Debo, as she was known, loved dogs, hens and Shetland ponies. She may have been a bumpkin, but she was incredibly well-met. Churchill and Kennedy were good friend, as were Harold McMillan, Alan Bennett, Evelyn Waugh, Lucian Freud and the Royal Family. She was photographed by the Beaton, Testino and, famously, by Bruce Weber, feeding her beloved chickens in a Balmain ballgown.

Deborah was the chatelaine of Chatsworth, one of England's grandest stately homes, for half a century. Following her death in 2014, Sotheby's announced that the Duchess' personal collection will be auctioned on March 2. Members of the public will be able to view the collection from February 27 to March 3.

A novelty brass lobster ink-well, a bumble-bee brooch, a first edition Brideshead Revisited: the lots paint a vivid picture of the bohemian Dowager Duchess. We're particularly enamoured with the earthenware hen tureens. A lifelong fowl-enthusiast, the Duchess acquired the hens in 1980, writing "In middle age when looking after my own chickens was too complicated, I gathered together pottery and china hens and ducks. They are less trouble than the live kind and are ever-present in my bedroom and sitting room."

Pop in to this exhibition and discover relics from a recent, vanished England.