Question: When did the British television period drama which has Joanna Horton included in one of its episode began airing? 
Sentence (from "Joanna Horton"): Joanna Horton is an English actress, notable for her stage and television work, including an episode of "Robin Hood" (series 1 episode 4), "Father Brown", "Spooks" and "Foyle's War".
Relevant evidence: Yes