Jim Broadbent has joined 'Game of Thrones'. The 67-year-old actor has signed up for a "significant" role in the seventh series of the popular HBO series but details of his character are yet to have been revealed, according to Entertainment Weekly. The forthcoming seventh season is to be filmed in Iceland, Spain and Northern Ireland and the seven episodes, three short of the usual 10-episode series, will premiere next summer. Jim starred as Horace Slughorn in the sixth 'Harry Potter' movie, 'Harry Potter and the Half-Blood Prince' and the final film in the franchise, 'Harry Potter and the Deathly Hallows - Part 2', and he is not the first star from the wizard movies to make the move to Westeros. David Bradley played Argus Filch in the 'Harry Potter' film series before going on to play the evil Walder Frey in 'Game of Thrones'. CiarĂ¡n Hinds starred as Albus Dumbledore's brother Aberforth in the wizard movies and then appeared as former Night's Watch member Mance Rayder. 'Game of Thrones' fans were recently left devastated after HBO programming president Casey Bloys confirmed the show will end after series eight. He said: "Yes, I think [the showrunners, D.B. Weiss and David Benioff] have a very specific plan about the number of seasons they want to do. If I could get them to do more, I would take 10 seasons but we want to take their lead with what they could do and what the best version of the show is." But he hasn't ruled out making a spin-off of the programme. He said: "We've talked about it. It's not something I'm opposed to but it has to make sense creatively. I'm not sure the guys can wrap their heads around it when they are about to start production. We're open to it; the guys aren't opposed to it but there's no concrete plans right now."