Gerard Butler as King Leonidas

While to most readers Gerard Butler may be an unknown commodity, he's been at this acting thing for a while now. With roles in films like "Tomorrow Never Dies," "Reign of Fire," "Timeline" and playing the Phantom in "The Phantom of the Opera," Butler's shown a wide range of acting ability, but it's his role as the King of Sparta in "300" that will begin to make Butler a household name.

Last weekend in Los Angeles, Butler spoke with members of the press about his role in "300," the intense amount of training and toll it took on him, and what this role means to his career. And don't miss our earlier one-on-one interview with Butler, right here on CBR.

Having finished the filming of "300," Butler explained how it felt to wrap up the much anticipated motion picture. "You always flounder for a few days. Especially the more of a transformation you've had to make," said Butler. "You have been, in a way, in someone else's mind and someone else's body. This role was a huge transformation for me." Not only did Butler need to get his head inside the mind of a King, he also underwent extensive and daily training to prepare his body for the part. "Then when you finish filming your whole routine changes and suddenly you don't have to do what you did anymore. It's kind of weird. You feel a little lost. You don't have to hold yourself the same way physically. I noticed in watching the video journals that even when I wasn't performing, I was still walking around as the king and talking like him. I don't do that anymore! I can slouch again! There was definitely a period of adjustment and physical pain because I stopped training. That was the worst thing I could have done."

While there's a lot of special effects and blue screen work involved in "300," Butler wasn't intimidated by the challenges involved. "I can't worry about the technology. The challenge for me is to give the best performance I can. However, you're right. You're always going to be aware that you're working in a different environment. Every film you do, for one reason or another, requires a different thought process or a different approach, and for me it's always leaving yourself open for that. Leaving yourself open to try to feel almost by osmosis the different feeling that's going on there, and then thinking about it as quickly as possible.

"On 'Phantom of the Opera,' I tried to learn so many things in the first few days about performing while singing. It's ridiculous things you wouldn't even think about. Like when you're singing, don't open your mouth so wide because you're on film and the camera can see everything. So there at '300,' it was definitely about trusting. Really trusting the world that you were living in. I think the temptation was to force it a little because there was nothing there. And some days you felt that you were performing in a vacuum, and in that respect using your imagination to create it might push you towards more theatricality or perhaps explaining things a little more, your voice. It was about trusting that and who you're dealing with. Your immediate partners in crime."

When asked what attracted him to "300," Butler explained, "It was the whole thing. If I read a script where I had an interesting character but I wasn't excited about the script I wouldn't do it, because that's happened before and I hated it. Likewise if it was a great script but a character I didn't love I wouldn't do it because I've done that before and I hated it. This film had it all. It was a character I'd never come across before. Yes, I've played similar characters, but I've never come across one who really pushed the envelope in terms of what it takes to be a hero and what it takes to be a villain. Because I have to say there were times when I thought, Jesus, these bad guys seem kind of nice. They're very reasonable! There's a confidence and arrogance about this king, even in terms of the political dealings with the messengers of Xerxes. It's quite risky in terms of keeping an audience in your favor. We kind of push that. There's never an apology about who they are. They stay focused and principled and never budge from that. It doesn't matter what action comes out of those beliefs. There's no conscience there in that respect when it comes to fighting, which I loved because as an audience member I'm always saying in my head to the hero, just fucking kill him! Kick the shit out of him! You know he's a bad dude! And in this, that's what they do! So I think it's really cool that at every turn it goes the way you wouldn't necessarily expect."

As King Leonidas, Butler takes great pleasure in the death of his enemies, but the actor tried to show some restraint in his protagonist's glee. "That's actually a very risky path to tread," said Butler. "If you focus too much on these men's willingness to die in battle, then their ultimate death doesn't mean a thing, because you know they're happy. I don't think as an audience you want to feel that. I personally felt very sad when they died because what had happened was in that uncompromising, unwavering belief that they had, at times which as I say can really make an audience go, 'Are these really the heroes?' By the end, you respect them for that very thing, because when you finally see that they were true lives, every single one of them. In terms of their commitment, their passion, their sacrifice. I did feel bad for them. Yeah okay, maybe those men are happy to die in battle, but we want to win. We want to take these 300 men and kick the asses of a million men. Yes, the sacrifice had a deeper meaning and in fact I believe that there was a deeper meaning with Leonidas. There was an element of mysticism, it wasn't even about these men dying for him. It was like he knew that 2,500 years later they were going to make a film about him. And not just that, it's gonna be a great film. There were many other things going on in his mind, but at the end of the day I think the focus had to be that they believed they could win."

Butler found his inspiration chiefly in the pages of "300" itself

Like many of his co-stars, Butler did some additional research to learn about his character and the world he was living in, but said that the "300" graphic novel was still his main source. "I did some historical research, but I have to say my experience is, and it's the same with Zack, you do all this research and you always end up, for me, probably 90% of where this character came from is Frank Miller's graphic novel. Often when you go too much into the past and bring up interesting facts, it only muddies the water of your story. There's really quite a simple true but yet mythological tale going on there. You know, the actual story was more complicated than what you see in the film, as is the story for every film, and that's for the History Channel to tell you about."

As for future projects, Butler was blunt about his plans, explaining, "I don't know. Going to bed. It's been weird because after 'P.S., I Love You' [with Hilary Swank], I couldn't do anything early on in the year because of this [press junket] and I was quite happy to take a rest, but now I'm in a really good place. I'm happy with what I have coming out. I'm going to wait and see what's going on."

CBR's Arune Singh and Andy Khouri contributed to this article.