The sixth installment of the highly popular period drama 'Downton Abbey' will most likely be the series' final season, as reported in this article by TV Line. The show continues to be a darling with critics while garnering strong viewership ratings around the world, but those factors won't stave off its eventual cancellation.

So far, no official statements have been released by either the network or its producers, but the decision to end the series at a sixth season likely stems from the majority of the cast's desire to move on to other projects. The contracts of many 'Downton Abbey' cast members expire following the upcoming sixth season and most have indicated that they would not return for a seventh season.

While this kind of talk has happened with the cast members of popular television shows before, it is unclear if this is merely a negotiation tactic of sorts for the 'Downton Abbey' team. Actress Maggie Smith had previously indicated, as per this article at Cinema Blend, that, in her mind, the show and her character were unlikely to continue past the sixth season.

"They say this is the last one, and I can't see how it could go on. I mean, I certainly can't keep going. To my knowledge, I must be 110 by now. We're into the late 1920s," she said.

Despite the sad news, the advance notice will most likely help Downton's creator Julian Fellowes in ending the series on a high note. This should make the upcoming sixth season all the more compelling and ensuring that the series goes out while on top, a feat that not all television shows can boast of.

The sixth season of 'Downton Abbey' is currently in development and an exact release date has yet to be confirmed.