Who is the lead actor in the British television period drama series that also featured English actress Joanna Horton?
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". Father Brown (2013 TV series): Father Brown is a British television period drama which began airing on BBC One on 14 January 2013. Father Brown (2013 TV series):  It features Mark Williams as the eponymous crime-solving Roman Catholic priest.
Mark Williams