'Game of Thrones' has made its first big casting announcement for the upcoming seventh season and it's a big one.

Academy Award and BAFTA winner Jim Broadbent is coming to Westeros for the season that star Maisie Williams has said that "nothing will prepare you for", joining the ever growing list of A-list talent chomping at the bit to join the critically acclaimed show.

As for who he's playing, well the jury's out on that. The infamously secretive 'Thrones' team have said nothing other than that his role is "significant", and now that we're well past George R. R. Martin's books, it's anyone's guess who Broadbent could be representing.

Our money, for what it's worth (and that's not much), is on him being a Maester in Oldtown who will either get in the way of or be of great aid to Sam as he learns the ways of the Citadel, perhaps someone who looks old and feeble but actually hides great cunning underneath it who taught/inspired Grand Maester Pycelle's charade that he stuck to until the bitter end.

Whatever it is, we'll have to wait to find out as 'Game of Thrones' isn't set to be back on our screens until the middle of 2017.

Via EW