It is no secret that Amber Anderson was joining the cast of Peaky Blinders, but the creators have kept the nature of her role close pretty quiet. After episode 2 aired, it was revealed that Anderson plays Lady Diana Mitford: a dark, strong, and dangerous leading character, and the love interest/mistress of Oswald Moseley. Anderson has previously appeared in the film "Emma", and on television in "Black Mirror", and "Strike".