India, Oct. 13 -- She sold 750 million books, but you would be hard-pressed to find one in a bookshop today. Barbara Cartland wrote 723 books over more than seven decades. They were translated into 38 languages, and at her most prolific she could produce more than 20 novels a year. Yet, for many people under 40, the books have disappeared. The pink clothes, enormous eyelashes, blond hair and Pekingese are more familiar than the novels.

Matthew Sweet's new biography, The Great Dictator: A Life of Barbara Cartland, looks at the life behind the costume of a woman who became an easy joke. Sweet had access to Cartland's archive at Camfield Place, where letters, manuscripts, appointment diaries and other material had remained largely untouched...