Los Angeles - Downton Abbey's ambitious cast forced the show to end.
The ITV drama's creator Julian Fellowes claims he had to wrap up the show after six seasons when the younger stars expressed an interest in moving onto other things.
He said: "I would probably have gone on for a bit. But the young actors joined for the most part as unknowns and now they are known everywhere. They want to test that."
However, the 66-year-old screenwriter feels "incredibly lucky" to be at the helm of such a successful show.
He added to the Sunday Times newspaper: "Downton has been a big thing for me. It's been a worldwide sensation for me. I consider myself incredibly lucky to have had one; I would be astonished if there was another."
And Julian has insisted that the upcoming Christmas special, and final ever episode, will be a great deal happier than last year's, where Matthew Crawley, played by Dan Stevens, was killed off.
He shared: "I don't think we're going to have a repeat of killing Matthew. People wrote saying, 'I will never watch anything with your name on it again.' I was absolutely deluged in it. People still come up to me in the street and say, 'I can't believe you would do that to my Christmas!' ... I think I can say that there will be a wedding in this series."
Watch the trailer for the final season here: