We already knew that Downton Abbey would return to PBS on January 5. Now we have an official UK air date. Season 4 of the hit period drama will kick off on ITV on September 22 at 9 PM in what will be the world premiere. As with last year, it will have X Factor UK as a lead-in. The Season 3 debut on September 16, 2012 drew 8.64M viewers, down about 200K from the previous season. However, overall Season 3 was the highest-rated season so far for the series with an average of 9.7M viewers. The show’s return is marked by the absence of Dan Stevens, whose Matthew Crawley character died in the Christmas special last year, and by the lack of Siobhan Finneran, whose O’Brien has also left the show. The rest of the Crawley clan and the below-stairs crew are returning along with Shirley MacLaine as Cora’s mother Martha Levinson. New this year, and for various stretches, are Tom Cullen, Julian Ovenden, Kiri Te Kanawa, Harriet Walter, Nigel Harman, Joanna David, Gary Carr and Paul Giamatti. The first episode of Season 4 picks up six months following the death of Matthew. The “spine” of the season will be the fate of his widow, Lady Mary Crawley (Michelle Dockery), as she heads to the next stage of her life, exec producer Gareth Neame recently told me.