Duke of Devonshire a separate title from that of Earl of Devon, which still belongs to the Courtenay family. The fifth Duke and Duchess of Devonshire are portrayed in the 2008 film "The Duchess" directed by Saul Dibb. The film is based on Amanda Foreman's biography of the scandalous 18th-century English aristocrat Georgiana Cavendish, Duchess of Devonshire (portrayed by Keira Knightley) and her relationship with the Duke (Ralph Fiennes) and his next wife, Lady Elizabeth Foster. Along with Jane Austen, the fifth Duke and his second wife appear, soon after Georgiana's death, in "Jane and the Stillroom Maid", a murder mystery by Stephanie
William Cavendish, 5th Duke of Devonshire wife Georgiana, Duchess of Devonshire. At the age of about twenty, Devonshire toured Italy with William Fitzherbert which is where they commissioned the pair of portraits by Pompeo Batoni. He was married twice: first, to Lady Georgiana Spencer (1757-1806) daughter of John Spencer, 1st Earl Spencer; second, to Lady Elizabeth Foster, née Hervey (1759–1824), daughter of the 4th Earl of Bristol; Lady Elizabeth had been his mistress and his first wife's friend and confidante for more than twenty years. By his first wife, he had one son (William Cavendish, 6th Duke of Devonshire, sometimes called "The Bachelor Duke", who succeeded