This week, the epic saga of THE HOBBIT comes to an end. We sat down with Richard Armitage to find out more about how he feels now the franchise is coming to an end, his motivations as Thorin Oakenshield and his recent joining of Twitter...

How do you feel now that THE HOBBIT franchise is finally coming to an end?

Richard Armitage: It's always coming to an end; it was coming to an end when e wrapped... It was coming to an end when we did the first film! I don't know if this will ever end; we will always be talking about it. Tolkien will certainly never end, there will be generations of people who will always read Tolkien, and I guess that's one of the joys of playing a character like this; one of my certainties is that I will be talking to a kid that's discovered The Hobbit and loves Thorin... That's nice because it will probably never die. ‘The road goes ever on' as they say.

How does it feel to work on the same story for so long?

RA: It's great. The thing is... I think releasing it over three years is interesting because you come back a year later and talk about it. It's nice to have been able to play a character's journey over a long period... To play a story over eight hours is very, very rare. It happens in television, but to put it on the big screen like this, and to have that trajectory of this character portrayed like that is a real gift.

The character is very complex and dark. How did you work out how dark you could take the character?

RA: That's the joy of working on a movie, because that exact thing is exactly what Peter [Jackson] and I were talking about, and he would shoot it. We'd go very, very dark and then look back at the edit and look at the shots that he's chosen, and he has gone to the place where we were scared to go to. We took a risk and we took him into a very dark place around the middle of this film, where he becomes consumed with the dragon's sickness. We allowed the character's psychology to be quite warped and inconsistent and psychotic. He doesn't turn into Hannibal Lecter, but he certainly becomes someone that you no longer trust, and whatever is happening in the mountain is screwy because of the psychology of the leader. That's exactly what needs to happen; you need to feel that everything is at stake because Thorin's mind is left him, and they're in trouble.

How did you approach this warped side of the character?

RA: I think I took the lead from Tolkien; he describes it as a sickness, a sickness of the mind. It had to feel like it was a temporary thing that he could recover from, because in order to leave the mountain and go to war, he did have to come back from a place that he'd descended to. We definitely played it as a sickness, as a mental illness.

What did you enjoy most about working on THE HOBBIT?

RA: I quite liked playing the despot, and some of those psychotic moments. They wrote Thorin so brilliantly; we would play a scene and then a few weeks later they would come back with another scene. They wrote a scene between Thorin and Bilbo, because it was really important to them to tighten up that relationship; Thorin becomes very isolationist in the mountain, and he becomes obsessed with Bilbo; everyone else is betraying him except him. It's leading us to the point where Tolkien has Thorin nearly throw Bilbo from the ramparts. For me, it was such a big part of the book, it was shocking at the time I read it, as a kid, so we were always driving towards that point. So it was just a joy to play those scenes with someone that's fevered in the mind... It's just great to play that.

You are probably the biggest Tolkien fan of the cast, and fans were upset at changes to the book, how did you feel about these?

RA: Am I? [laughs] The thing is I think all of those decisions get made to enable the story to just have a more dramatic arc. I think that Tolkien himself went and wrote The Lord of the Rings because The Hobbit wasn't quite enough of Middle Earth, and he wanted to expand on that idea. I think Peter's probably doing the same thing; he just explores paths that Tolkien shows us but doesn't tread. If you look at The Battle of the Five Armies... Tolkien does a Shakespearean thing; he talks about it in retrospect, he doesn't really go there with the audience. I remember being a little bit disappointed when I was a kid, and thinking ‘I want to know more about that battle' and I think Peter does too. I don't think he necessarily changed things; he added things... Personally I was disappointed that he never showed the Elf Rings in the forest, that was something that I was looking forward to because I played it on stage when I was a kid, so everyone has something that they're looking forward to and they'd miss, but ultimately, Peter's reimagining a story, and using Tolkien as a blue print.

Most kids who read THE HOBBIT identify with Bilbo; which aspect of the book did you identify with the most when you first read it?

RA: The thing that had the most impact for me when I read the book was Gollum, and you often forget that Gollum is in the story when you get to the end of it, because he's such a contained character. I remember re-reading that scene in Gollum's cave, and I think that that is one of the reasons why Tolkien wrote The Lord of the Rings; because he too was obsessed with what happened in that cave, and the Ring. The Ring didn't have the same potency that it took on for The Lord of the Rings, and it's almost like Tolkien gave himself and idea by writing it and went back to it. I guess re-reading the book as an adult, knowing I was going to play Thorin, of course I connected with Thorin, and I disagreed with his choices throughout most of the journey; I was very angry with Thorin and at odds with the character. That was one of the reasons that I wanted to play him; there is nothing better than disagreeing with everything that your character chooses to do, because you've got some great conflict going on between actor and character.

How do you act something that you disagree with?

RA: It's about like playing a mass murderer; I had to get into a position whereby if I was put on trial as Thorin, I would be able to absolutely get off scot-free with what I had done, and defend him. He's proud and stubborn, and there is a side of me that has that same proud, stubborn, pig headedness that often gets me into deep s**t. I work hard not to be that person, but the opportunity to play someone who was desperately pig-headed and stubborn was irresistible.

You wore so much makeup, prosthetics and wigs to transform yourself into Thorin, do you miss that on the projects you have worked on since?

RA: There is always a transformation, whether or not it's a huge one; even if it's the kind of jumper that your character is wearing. They are just smaller, but you always make some kind of transformation.

Did you find filming with a green screen fun, or was it challenging?

RA: It depends what kind of mood you're in, actually. In general, I really really enjoyed that side of it. I know some actors struggle; I know Ian [McKellen] was less fond of it. Once you let yourself go and you've got Peter's description, and your own imagination... I can imagine whatever the hell I like, no-one's ever going to know what's going on in my head, as long as something's going on in my head! It can be immense fun; I would get to the end of a take and look over at Graham [McTavish] and be like ‘what were you imagining?' and he was like ‘Oh some big, blue, three headed thing' and I'd be like ‘Wow. I've got to think bigger.' It was good fun, I enjoyed it.

You recently joined Twitter (@RCArmitage), how are you enjoying it?

RA: I still don't get it, and I forget to do it. I guess I did it because I needed to diffuse some of the anxiety that was happening, and remind people that it's supposed to be fun, and reminding myself that it's supposed to be fun... Going to the film, supporting the film, and promoting the film is supposed to be fun. With THE HOBBIT, we cover a big demographic; kids with drag their parents who don't want to come and see the movie, and Twitter is a way of nagging the parents through their kids.