Hugh Bonneville has said that Downton Abbey will have a "natural" conclusion.
The actor plays Robert Crawley in the ITV drama and says the show will reach its halfway point with the upcoming fifth season.
"Audiences abroad don't quite appreciate that it's written by one person," he said. "There's only so much that one person can do.
"There will be an end. [Producer] Gareth Neame has said that it will run between five and ten years. We've made it to halfway. There will be a natural end, and I'm sure [creator and writer] Julian [Fellowes] will want to quit while he's ahead."
Bonneville also praised the ongoing storyline involving Thomas Barrow (Rob James Collier) and his struggles with being gay - which was illegal in the UK in the early 1900s.
"I'm particularly fond of the character of Thomas Barrow and the fact that he's gay and it's against the law," the actor added.
"I like the way that my character handles that and is tolerant, in a society that was intolerant and prejudicial.
"Having been an out-and-out monster by series two, by series three you actually care for [Thomas] greatly. He still gets up to his old tricks though, he's still a s**t.