Downton Abbey: Julian Fellowes plans a prequel 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. Fellowes said the drama would be shown when Downton Abbey draws to a close. "I don't think you can continue a narrative in more than one area at once," he explained. I never really liked those Coronation Street Christmas specials where they all go to Haiti, and you don't have to watch it. Somehow it doesn't feel very organic. The latest series of the ITV costume drama features Cora's mother, Martha Levinson (Shirley MacLaine), whose straight-talking American ways are anathema to Dame Maggie Smith's Dowager Countess. Speaking as part of the Bafta Screenwriters" Lecture series, held at the British Film Institute, Fellowes hinted that a Downton play or feature-length film could also be under consideration. ITV executives hope to prolong the "Downton effect" for as long as possible after the show brought record drama audiences to the network. However, some of its leading stars, including Dan Stevens and Michelle Dockery, are expected to leave at the end of this series in pursuit of Hollywood stardom. In his lecture, Fellowes, 63, recalled a time when costume dramas were deemed unfashionable. Commissioned to write an adaptation of Frances Hodgson Burnett's Little Lord Fauntleroy for the BBC in 1995, he was brought up short by Alan Yentob, then controller of BBC One. Fellowes recalled: "I'll never forget that Alan Yentob had an advisory body of some sort, and they sent him in a report after reading my scripts. "It said, "The market for class-based period drama is dead." Happily for the rest of my life, this proved inaccurate. Eagle-eyed viewers delight in spotting historical inaccuracies in Downton Abbey, but Fellowes said he invested a lot of time in getting the details spot on. If you get the details of something right, even for people who know nothing about it, it takes on a kind of credibility. "So if you know that footmen don't knock on a ground floor sitting room or a library, but they do knock on a bedroom door, there's a sort of logic that makes it feel believable," he said. Fellowes, who spent years as a character actor, said he owed his current success to the US director, Robert Altman, who hired him to produce the script for Gosford Park. It earned Fellowes an Oscar for best screenplay. He said: "I do feel very strongly that America rescued me. All the stuff in England, the stuff we have about each other, they don't care about all that. They care about whether your last picture did anything or what you're doing next. They allowed me a promotion within the business that I would not have been allowed by my British contemporaries. On finding success later in life, Fellowes said: "People say to me, "Wouldn't you rather this had all happened when you were 30?" Well, the short answer to that is yes, but the long answer is that by the time you're 50 you've made a fool of yourself so many times that the thought you might make a fool of yourself is no longer a deterrent. So you just cheerfully take it on board and have a crack.