He became a household name in his 20s as Princess Diana's favourite designer, and later created the wedding dress for Princess Margaret's daughter, Lady Sarah Armstrong-Jones. Now aficionados of Jasper Conran — son of late Habitat founder Sir Terence Conran and Superwoman author Shirley Conran — are about to have a unique chance to own some of his own personal treasures. For I can disclose that Conran junior is auctioning the entire contents of his exquisite 23,000 sq ft, six-bedroom apartment at New Wardour Castle, Wiltshire. The three-day auction, which will be conducted both in the sale room and online in September, promises to be one of the highlights in Christie's calendar.