Julian Fellowes Creator, Executive Producer, Writer Cynthia Nixon Ada Brook Actor Morgan Spector George Russell Actor Denée Benton Peggy Scott Actor Louisa Jacobson Marian Brook Actor Blake Ritson Oscar van Rhijn Actor Simon Jones Bannister Actor Harry Richardson Larry Russell Actor Jack Gilpin Church Actor Ben Ahlers Jack Trotter Actor Mike Cerveris Mr. Watson Actor Celia Keenan-Bolger Mrs. Bruce Actor Debra Monk Mrs. Armstrong Actor Kelli O'Hara Aurora Fane Actor Patrick Page Richard Clay Actor Taylor Richardson Bridget Actor Douglas Sills Monsieur Baudin Actor Erin Wilhelmi Adelheid Weber Actor Sullivan Jones T. Thomas Fortune Actor David Furr Dashiell Montgomery Actor Ward Horton Charles Fane Actor Michael Engler Director, Executive Producer Gareth Neame Executive Producer, Director David Crockett Executive Producer Salli Richardson-Whitfield Director, Executive Producer Sonja Warfield Writer