Hary-O, as she was called, was born in 1785 to the beautiful Georgiana, Duchess of Devonshire and incurable gambler, and the 5th Duke, who seems to have passed his life largely disengaged from his surroundings. With her elder sister Georgiana, who became Lady Morpeth then eventually Countess of Carlisle, and younger brother William, always known as Hart, the bachelor 6th Duke, she formed an unrivalled mutual admiration society. Whenever they were apart, they were the most assiduous of correspondents, which means that we can enjoy Hary-O’s mordant wit and shrewd commentary through her letters to them. She once strikingly invoked Georgiana: ‘O sister of my own sort, liver of the chicken to which I am gizzard.’