Ian McShane made a name for himself in America starring as the foul-mouthed Al Swearengen on HBO's Deadwood. The actor is finally returning to the pay cable network that kick-started his career. He is taking a part on the hugely popular fantasy drama series Game of Thrones. Though, it isn't known whom he will be playing yet.

Ian McShane's role in Game of Thrones Season 6 is said to be small. But it will be pivotal. EW broke the news, stating that the unnamed character will only be seen very briefly. But this person is of 'key importance'. No further details have been made known, and likely won't be for some time, as the role is to remain a mystery.

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Game of Thrones Season 6 is currently shooting in Belfast, Ireland. But it isn't known if that is the location Ian McShane will be flown too for his extended cameo. No specific shoot date is given for the Emmy winner's appearance on set, but it is said that he will shoot his scenes after he finishes his current stint on Showtime's Ray Donovan. This casting news comes just days after HBO president Michael Lombardo confirmed that the series will run for at least 8 seasons. It could go for more, but the game plan is to complete three more seasons before bringing everything to a close. A prequel series has not been ruled out, and is entirely possible.

A report from May revealed that Game of Thrones Season 6 will introduce 26 new characters. Of the characters, Randyll Tarly, the father of Samwell Tarly (John Bradley), is most likely whom Ian McShane is playing. The role is described as a man in his 50s or 60s, one of the greatest soldiers in Westeros history, a "humorless martinet" who is severe and intimidating. The character will have a "very good part" next season and will be "centrally involved" in one of the protagonist's story lines.

Another possibility is Euron Greyjoy, the uncle of Theon Greyjoy/Reek (Alfie Allen). The character is described as a pirate in his late 40s to early 50s, who has "terrorized seas all around the world," and is "cunning, ruthless, with a touch of madness." There is also the part of a Priest in his 40's or 50's. A gruff ex-soldier who found religion. Now a no-nonsense rural priest who ministers to the poor of the countryside. He's a salt-of-the-earth man who has weathered many battles. Of the many roles hinted at, these are the three that best suit an actor like Ian McShane.

Also possible fits are Lord of Noble Northern House, described as a large bearded man with a violent temper, who the producers want to tower over the other actors and have a strong Northern English accent. There is also a Lord of Northern Stronghold character, described as "ruthless, calculating and terrifying," who will appear in three episodes. At this point, with 26 never-before-seen characters coming into the mix, it's hard to pinpoint with any accuracy who Ian McShane may take on when he arrives in Westeros. And we may have to wait until Game of Thrones Season 6 arrives in April 2016 to know the true answer. The TV show has caught up with the books, so there may be even more new characters that no one even knows about yet!