Bessie Carter Nancy Mitford Actor James Purefoy David Freeman-Mitford Actor Calam Lynch Bryan Guinness Actor Anna Chancellor Sydney Bowles Mitford Actor Toby Regbo Tom Mitford Actor Joanna Vanderham Diana Mitford Actor Joshua Sasse Oswald Mosley Actor Isobel Jesper Jones Pamela Mitford Actor Will Attenborough Joss Actor Jamie Blackley Peter Rodd Actor Zoe Brough Jessica Mitford Actor Shannon Watson Unity Mitford Actor Sarah Williams Writer Joss Agnew Director Ellie Heydon Director