NEW YORK — A grand manor will close its doors to millions of weekly guests after “Downton Abbey” concludes next year.

Producers of the popular British period drama Thursday confirmed it will end after its sixth season, scheduled to air in the United States in early 2016. The series, which airs earlier in the U.K., will have its finale on Christmas Day 2015.

“Our feeling is that it’s good to quit while you’re ahead,” executive producer Gareth Neame said. “We feel the show is in incredibly strong shape, the scripts that we’re working on for the upcoming season are fantastic and the show is so popular globally. But the danger with this sort of thing is to let it go on forever.”

He said the decision to wrap was made by him and Julian Fellowes, who created the series and has written every episode, in conjunction with the cast.

He said there are no plans in place for a rumored “Downton Abbey” feature film or a series spinoff.

The acclaimed, beloved and awards-showered drama has tracked the fates of the aristocratic Crawley clan and its servants amid the social upheavals of pre-World War I Britain into the 1920s, as the characters of upper and lower classes cope with their rapidly changing world.

Stars include Hugh Bonneville, Jim Carter, Michelle Dockery, Elizabeth McGovern and Maggie Smith.

The series premiered on the U.K.’s ITV network in 2010 and on PBS’ “Masterpiece” anthology in early 2011, inspired in part by the 2001 Robert Altman film “Gosford Park” (written by Fellowes) and presented as a variation on the British classic “Upstairs, Downstairs.”

“When we set out to do this in the first place,” Neame said, “we thought we would have a good success in the U.K. and that very traditional outlets for British content globally would be there.”

But almost instantly “Downton Abbey” took on a life of its own.

“We did not know we would be in 250 territories worldwide,” Neame said. “We didn’t know we would be one of the biggest shows on American television.”

In the U.K., it became the highest-rated drama of the past decade, with an average of 11 million viewers over its five seasons. Season 5, which concluded in the U.S. this month, drew an average audience of 12.9 million viewers.

“Masterpiece” executive producer Rebecca Eaton called the series “a gift from the television gods.”

She said it coincided with the 2009 rebranding of “Masterpiece,” which, among many changes, led to dropping “Theatre” from its title.