Among the six daughters and one son born to David, second Lord Redesdale, and his wife Sydney were Nancy, the novelist and historian; Diana, who married fascist leader Sir Oswald Mosley; Unity, friend of Hitler; Jessica, who became a communist and then an investigative journalist; and Deborah, Duchess of Devonshire and mistress of Chatsworth. 'The Mitford Girls,' as John Betjeman called them, were one of the twentieth century's most controversial families; said to be always either in shrieks of laughter or floods of tears, they were glamorous, romantic and - especially in politics - extreme. Yet the teasing, often bordering on cruelty, the flamboyant contrasts and the violent disagreements, hid a powerful affection, subtle likenesses in character, and a powerful underlying unity.
Jonathan Guinness is the elder son of Diana Mosley by her first marriage to Bryan Guinness, now Lord Moyne. He has worked in journalism and banking. Catherine Guinness is the eldest of his five children. She has been a journalist with Interview magazine and has also worked for a firm of investment advisers. She is married to James, Lord Neidpath, the historian.