Michelle Dockery
Actress Michelle Dockery, from the PBS series "Downton Abbey," arrives at the 65th Primetime Emmy Awards in Los Angeles Sept. 22, 2013. Reuters/Mario Anzuoni

The much-awaited fourth season of British period drama “Downton Abbey” is all set to return to MASTERPIECE on PBS on Sunday.

The premiere show opens six months after last season's great tragedy where Lady Mary Crawley seemed inconsolable after the death of her husband, Matthew, who died in a car accident. Mary is shown as being steeped in grief and the Crawleys' financially fragile estate stumbles into yet another crisis.

Gareth Neame, an executive producer of the show, said on PBS's website: “If there’s a theme to the fourth season, it’s how Mary will rebuild her life."

The modern world of 1922 draws Downton’s youth with its jazz clubs and literary scenes, promising social change and threatening the very existence of Downton Abbey. The Crawley family's reaction to such a threat, and how the clan deals with it behind the abbey's ancestral walls, will be seen over the course of the current season.

“Downton Abbey,” with its clever portrayal of British social history and the class differences of a bygone era that contrast with contemporary notions of equality and democracy, has managed to draw huge audiences in the U.S.

“Like millions of other ‘Downton Abbey’ fans, I can’t wait to see what’s next for the Crawley family,” said Paula Kerger, president and CEO of PBS.

The show recently completed its fourth season run in the UK where it drew an average of 11.8 million viewers, making it Britain’s highest-rated television drama in 2013. In the U.S., the show's third season received more than 24 million viewers making it the most watched drama in PBS history.

"Downton Abbey" has won 10 Emmy Awards and two Golden Globe awards, and the previous season’s finale drew 8.2 million U.S viewers. The show's fourth season will feature Maggie Smith, Hugh Bonneville, Elizabeth McGovern, Michelle Dockery, Shirley MacLaine and Paul Giamatti among others.

“As American audiences ready themselves for the January 5th premiere of Season 4, our devoted Downton Abbey Fans will rest easy knowing that a fifth season is on the way,” Rebacca Eaton, executive producer for MASTERPIECE, said, on PBS's website.