23/12/2015 00:01 GMT | Updated 22/12/2016 05:12 GMT

Downton Abbey Takes On Walford In Christmas Day Ratings Battle

Downton Abbey's final episode is broadcast on Christmas Day, but it will face stiff competition from EastEnders as it battles to go out on top in the ratings.

Viewership for the Christmas Day episodes of ITV's drama has fallen with each successive year since the first special was broadcast in 2011.

An average overnight audience of 8.6 million viewers, including those time-shifting on ITV +1, watched as Matthew Crawley (played by Dan Stevens) proposed to Lady Mary (Michelle Dockery) four years ago, according to the Broadcasters' Audience Research Board (Barb).

However, the period drama increased to an impressive 12.1 million viewers when consolidated figures, which take into account viewers watching via catch-up services, were released.

Last year's special in which Tom Branson (Allen Leech) departed for a new life in America was seen by an average overnight audience of 5.8 million viewers, including those watching on ITV +1.

It rose to consolidate to 7.7 million viewers.

Downton Abbey was scheduled against the BBC One soap last year, but the Walford-set show triumphed with an overnight average of 7.5 million viewers.

ITV's costume drama will go up against the residents of Albert Square for the final time on Christmas Day.

The battle for viewers will be keenly contested as the feature-length special promises changes for the Crawley family and their loyal servants.

Lord Grantham (played by Hugh Bonneville) and Lady Cora (Elizabeth McGovern) prepare to celebrate an unforgettable New Year's Eve at the great house.

Butler Carson (Jim Carter) is philosophical about the new developments at Downton.

"I hope you're not too unhappy about the way things have turned out," the aristocrat tells his employee in the trailer released by ITV.

"The world is a different place from the way it was, my lord, and Downton Abbey must change with it," Carson replies.

Henry Talbot (Matthew Goode) settles into the role of husband to Lady Mary (Michelle Dockery) and stepfather to little George.

Meanwhile, Lady Edith (Laura Carmichael) encounters Bertie Pelham (Harry Hadden-Paton) and the family and servants will apparently bid farewell to controversial figure, Thomas Barrow (Rob James-Collier).

"I arrived here as a boy, I leave as a man," he tells those assembled, as George begs him to stay.

The Dowager Countess, played by the scene-stealing Dame Maggie Smith, observes: "Every year we drink to the future, whatever it may bring."

Lily James, soon to be seen in BBC One drama War And Peace, reprises her role as Lady Rose Aldridge.

Patricia Hodge, best known in recent years for her role in BBC One comedy Miranda, will play the mother of Bertie Pelham.

Matt Barber returns as Lady Rose's husband Atticus and Peter Egan is also back as Lady Rose's father, Hugh MacClare, Marquess of Flintshire.

The series finale also features regular cast members Penelope Wilton as Isobel Crawley and Samantha Bond as Lady Rosamund Painswick.

The much-loved actors playing the servants, including Phyllis Logan, Brendan Coyle, Joanne Froggatt, Lesley Nicol and Sophie McShera, will take their final bow.

Downton Abbey debuted on ITV in 2010 and became a global phenomenon, collecting numerous awards along the way.

It also grew into a pop-culture favourite with spoofs and parodies from Sesame Street and The Simpsons, to name a few, lighting up social media.

The finale will mark the end of a true trailblazer of British television history.

::Downton Abbey and EastEnders are both broadcast at 8.45pm.