A year ago she was an unknown schoolgirl more interested in seeing her friends in Brighton than mixing with A-listers on the red carpet.

But Dakota Blue Richards has been plucked from obscurity to play the starring role in what is set to be one of the biggest blockbusters of the decade.

Dakota, 13, will play Lyra Belacqua in the movie adaptation of Philip Pullman's His Dark Materials trilogy which premieres across the globe in December.

The first film in the putative trilogy, to be called The Golden Compass, has been made by New Line, the company behind The Lord of the Rings films.

Ten thousand girls turned up for open auditions in Cambridge, Oxford, Exeter and Kendal. But it was Dakota who caught the casting directors' eye in Cambridge.

Marketed as the "follow-up" to Lord Of The Rings by makers New Line studios, it cost £180 million to make.

Dakota said: "It's a bit strange now because the first poster is at the cinemas and it's a weird feeling I get seeing it. It's sort of me, and not me, if you know what I mean."

The books have sold ten million copies worldwide and are adored by legions of fans, including Dakota herself whose mother read them to her when she was nine.

The young girl got the part after a friend of the family, watching kids TV show Newsround, saw that the film was going to be made.

The author then helped pick her out from 10,000 prospective Lyras who attended auditions.

Dakota said: "My mum and my grandma and me went to the casting call in Cambridge. My mum said we wouldn't go if the weather was bad, so it was lucky it wasnít raining.

"We waited in the queue for about three hours, and we went into the audition in groups of between 50 and 100 girls.

"I was called back with about 60 other girls to the casting office in London.

"But being called back was like being given a real chance, and you know itís time to start worrying."

Pullman has said of Dakota: "She's absolutely marvellous - and she looks right. I know Lyra better than anyone. Looking like someone isn't a case of having blond hair and blue eyes: it's about bone structure; the way someone carries herself.

"She is also a very good actress."

Director Chris Weitz, who pretended to be armour clad polar bear Iorek Byrnison in her auditions, added: "We were not just casting an actor, we were also casting a family situation.

"She had to handle the strain of acting and, when not acting, going to school. She had the hardest job."

The movie was shot at Shepperton Studios and on location in Iceland and Oxford.

But, although Kidman and Craig are likely to draw big audiences, special effects creatures such as the polar bear voiced by Sir Ian McKellen are expected to thrill the fans.

Dakota said: "The first scene I did in the film was with Nicole Kidman. I didnít have to say anything, thankfully.

"But a lot of the time I had to act to nothing, or to a green sack, or a green dot or a man in a green lycra suit."

The film cost almost twice as much as Peter Jackson's Fellowship Of The Ring but if successful it is sure to be followed by Pullman's sequels - The Subtle Knife and The Amber Spyglass.

Dakota is hoping she could then return as Lyra and has no qualms about missing out on school.

She said: "We had a schoolroom at the studio and I had lessons, sometimes for half an hour, sometimes for a couple of hours. I never knew how long.

"It was quite difficult to switch from being on the set to being in the schoolroom, but I must have learnt a lot because when I got back to school I was quite far ahead."

For the full interview with Dakota see The Guide on December 7.