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
The Duchess (film) comes to live with them while Georgiana is pregnant. William expects Georgiana to tolerate the presence of the child who turns out to be his own illegitimate offspring. He also suggests that she "practice mothering" on the young girl. When Georgiana gives birth to a girl, William is displeased. In his mind he has fulfilled his obligations to her as her husband but, by failing to provide him with a legitimate male heir, she has failed in her obligations as his wife. Georgiana socializes with the young Lady Bess Foster at Bath and kindly invites her to live with them,