ORLANDO BLOOM seems to live a charmed existence on and off-screen. By rights he should be dead, or at least paralysed, after he broke his back falling three storeys from a friend’s roof terrace in 1998. Instead, he walked out of hospital 12 days after the accident. Then there’s the way he was cast as Legolas in the Lord of the Rings trilogy while he was still at drama school. He jumped from that to last summer’s blockbuster, Pirates of the Caribbean, and now he’s starring alongside Brad Pitt as Paris in Troy.

Add the facts that he has landed the lead role in Ridley Scott’s Crusader epic Kingdom of Heaven, and that he’s dating the rising young Hollywood actress Kate Bosworth, much to the chagrin of his vast and vociferous fan club of teenage girls, and it’s enough to make you think that Bloom has done a deal with the Devil to guarantee success in all spheres of life.

“I think I put in the legwork at quite a young age in terms of trying to make sure that I was in the right place at the right time,” claims a disappointingly un-satanic Bloom on the set of Troy in Malta.

“I moved to London to go to drama school when I was 16, so I kind of geared myself up at a young age to put myself in the right arena to become an actor and get work. I think the biggest compliment for me was just getting work.”

But nothing he’s done so far can match the scale of Troy. A $200 million (£111 million) retelling of Homer’s poem The Iliad, it’s a throwback to classic epics such as Ben-Hur and Spartacus; the size of the production makes the Lord of the Rings saga look small in comparison. “This feels so much bigger in so many ways. The money, the vastness of the sets, and I’m playing more of a principal role,” says Bloom. “That means you assume more responsibility, and it forces you to be more immersed in things.”

As Paris, the Prince of Troy who steals Helen from her husband the King of Sparta, it’s Bloom who is responsible for sparking the war that The Iliad chronicles. For the first time in his career, he’s playing the villain of the piece. “I like to call him an ‘anti-hero’,” grins Bloom, whose hair is back to its natural dark brown for Paris. “But yeah, it is all caused by the selfishness of this young man.”

It is a far more complex part than Legolas, or Will in Pirates of the Caribbean, and Bloom knows it is the perfect opportunity to prove that he is more than just a pretty face.

“There’s quite a lot of pressure. You feel the responsibility of trying to make it believable and real, especially as The Iliad is like the story of stories,” he acknowledges. “It’s interesting, I don’t want the audience to hate Paris because of what he’s done, but the odds are stacked against me in terms of what his actions are. That was the interesting thing about the role when I read the script. He goes from being young and irresponsible to growing old very quickly.”

You can’t say the same for the 27-year-old Bloom. He’s an exuberant, slightly self-satisfied character and there’s a sense that he has yet to come to terms with his rapid rise from unknown to star. “I try not to think about it too much and just get on with things,” he confesses. “It’s great, though. I’m getting to work in movies and it’s amazing. I’m living most actor’s dreams.”

He has had the advantage of being able to tap for advice some of the most successful stars around, such as Pitt and Johnny Depp. “I said to Johnny on Pirates, ‘Isn’t it crazy how much money we get to do a job that we love?’ and he said that privacy and trying to live a normal life become quite expensive. I mean, there are suddenly a lot of people in my life who weren’t there before and they’re all on the payroll.”

Some of those new staff deal with the mounds of fanmail he receives: “It’s quite an ordeal, because there is so much of it.”

If there’s one small blip on the Bloom radar, then it’s that he seems far more comfortable in period pieces than he does in modern-day roles. He made his film debut as a 19th-century rent boy in Wilde in 1997, and he was back in the same era, only in the Australian outback, for Ned Kelly last year. But he seemed out of place in the recent The Calcium Kid, a low-budget, British contemporary comedy. Bloom doesn’t seem to care though.

“I love to dress up; I love to get into character through costume and period,” he says.

His preference for period parts might stem from his lack of interest in current events, something that’s exacerbated by the fact that he is constantly shuttling between London, LA and film sets around the world. “I’m not particularly up on popular culture. I watch a lot of movies and sometimes I flick through magazines on planes. But I don’t go out and look for it. I suppose I am hippy-ish. I’ve never been into the latest band or anything. I don’t buy into any of that,” shrugs Bloom.

Instead, he was obsessed by acting from an early age. “I got inspired by seeing larger-than-life characters in films, on stage and even street performers. I was very young.”

Born and brought up in Canterbury, he moved to London as soon as he could, and spent two years with the National Youth Theatre. From there he progressed to the Guildhall School of Music and Drama, where he auditioned for Peter Jackson, director of Lord of the Rings.

Bloom admits that he would have been happy with any part in the trilogy; he was originally chosen to play the much smaller role of Faramir. “I think as a young actor you take what you can get. At the beginning of your career, you can’t expect to get certain roles. I do think that there’s a rite of passage in this industry. I’d love to be playing dark character roles, maybe contemporary ones sometimes, but it’s about what scripts you get.”

Perhaps the 18 months he spent in New Zealand filming Lord of the Rings have spoiled Bloom, who seems happiest working on large-scale productions. “I do like doing these big movies. I feel quite at home on a big set now, which I think is a very fortunate position to be in. I’ve been lucky that I’ve got to work on epic-style films, films that feel to me that they will stand the test of time.”

Now it’s up to Bloom to prove that he can do the same.

Troy opens May 21 - www.troymovie.co.uk