I do actually have an idea of doing a prequel of the courtship of Robert and Cora, when all those American heiresses were arriving in London. They had a slightly troubled courtship, because she was in love with him before they married, as we know, and he married her entirely for her money... I sort of feel there's something quite nice in there because he's a decent cove, and so he feels rather guilty about this which has affected their marriage beyond that.
While Fellowes spoke about the potential project as a book, it seems likely that it would also yield a screen adaptation, given the phenomenon that "Downton Abbey" has become. An early series would take the setting back to the 1800s, and would involve new actors in the roles of young Robert and Cora. Fellowes told the crowd that any prequel would have to wait until the main "Downton Abbey" run is over: "For me, any other books or plays or films should follow after the end of the television show. I don't think you can continue a narrative in more than one area at once."
The third season of "Downton Abbey" is currently airing in the UK and will have its US broadcast premiere on PBS on January 6th of next year. In addition to his TV drama, Fellowes has worked as an actor (most recently on "Monarch of the Glen") and a screenwriter -- he won an Oscar in 2002 for the script for "Gosford Park."