"We are delighted to welcome these talented actors to the world of 'Downton,'" Gareth Neame, the show's executive producer and managing director of Carnival Films, said in a statement Friday. "The characters they play are set to bring yet more excitement and intrigue to the show."
"We look forward to introducing these new characters to our Masterpiece audience. They will make a wonderful addition to the beloved 'Downton Abbey' ensemble," said Rebecca Eaton, executive producer of PBS' Masterpiece programming banner.
Season 4 of the show is to wrap up its U.S. run Feb. 23.