Great ex-pec-tations

Last week, against all predictions, a fairly good sword 'n' sandals flick with no big stars, based on an obscure comic book about the ancient battle of Thermopylae, broke US box office records. The tersely titled 300 in fact took the equivalent of £36million in its opening weekend. The big question is, why?

'You know? I have NO idea!' grins its fast-talking US writer/director Zack Snyder, with cheery honesty.

'The truth is, we made the movie for $60million (£31million), which in Hollywood terms isn't vast. I thought, if we stayed really, really consistent to the very particular aesthetic and radical vision of Frank Miller's graphic novel, we'd create a movie experience that at least feels slightly original. Maybe that's it?'

Maybe. The dreamy look of 300 is certainly a unique draw. And the battalions of oiled six-packs can't hurt. Like previous Miller adaptation Sin City, 300 combines dazzling virtual backgrounds with racy live action and an intelligent script, fleshing out macho mythology with Orc-tastic battle scenes and blood-drunk heroes. 'I feel it's far closer to Pirates Of The Caribbean than Alexander,' admits Snyder.

The truth is, though, no one can really answer why what Snyder calls 'a niche, almost indie genre, movie' such as 300 has attracted such wide appeal. Certainly not the bemused ensemble cast of mainly British barely-knowns gathered in South-West London's Berkeley Hotel this morning.

Jiggling his massive knee as if he'd rather run off and strangle a lion than answer press questions, Scottish leading man Gerard Butler (best known for the film version of The Phantom Of The Opera) is clearly hideously embarrassed at the idea of being the new Russell Crowe. No wonder, given we, like the 300 poster, are focused on his epic abs.

'I trained for six hours a day, even before our eight-week boot camp in Montreal. I got a bodybuilder. I pumped all the time on set. I trained at lunchtimes, I trained at weekends. I made that my focus - emotionally and psychologically. The Spartans trained like buggery.'

Butler rocks intently back and forth. As does the table in front of him. 'Only after 20 years of training were they allowed - maybe - to become a Spartan soldier. I wanted to be worthy of that. And I don't mean that in a bullshitty way. I was working with great actors. I had to be their king. Plus, I'm a really paranoid person. I didn't want them to think "he's a dick who doesn't prepare".'

Butler is King Leonidas, a hero who leads just 300 Spartans against Xerxes and his massive army of decadent Persians - all to protect Western democracy.

It is a scenario that has, predictably, stirred up controversy, even though war on terror parallels are hardly explicit. At a recent New York press conference, one journalist was reduced to asking: 'Is George Bush Leonidas or Xerxes?' Snyder's answer? Neither.