Ben Barnes has the title role in The Chronicles of Narnia: Prince Caspian, the second film adaptation of the fantasy series by C.S. Lewis. Barnes’ flowing tresses have earned him an ardent audience of teen girls.

AP / Murray Close

There’s a changing of the guard in the Walden-Disney movie franchise The Chronicles of Narnia. The young actors who were the leads in 2005’s The Lion, the Witch and the Wardrobe and in the new film, Prince Caspian, are giving way to the title character in that second film. Ben Barnes, a 26 year-old British stage actor best known for his work in the theater and a few small film roles, plays Prince Caspian, introduced in Prince Caspian and the leading figure in the next chronicle, The Voyage of the Dawn Treader.

Is the franchise in good hands? Variety seems to think so.

“Barnes has the dark, dashing looks that will make teen girls turn out more than they normally would for a battle epic,” Todd McCarthy wrote.

A quick poll of enthusiastic teenage girls leaving an Orlando preview screening of Prince Caspian reveals his real appeal.

“His hair.”

Barnes, on the phone from Los Angeles, laughs.

“I can’t take credit for that,” he protests. “It’s not actually my own hair. It’s extensions!”

Barnes is trying to roll with it, this sudden stardom thing. He had read C.S. Lewis’ books as a child and remembered them. He knew the first film made a staggering $745 million worldwide back in 2005-06. He knew what he was getting into when he signed on to Disney’s biggest film franchise — years of commitment, film fame, all beginning with months of training.

“Seven hours a day, every day, on a horse, in New Zealand, for starters,” he says. “We shot almost chronologically; the film begins with a big chase on horseback, so I had to be ready for that. Lots of sword-fighting training, too. Dialect coaching so I could do this Mediterranean accent. I felt like I was at Narnia boot camp!”

The blast of attention isn’t as daunting for the young actor as you might think. The son of a psychiatrist dad and therapist mom, Barnes grew up in a house where people “were always asking you, ‘How do you feel?’ ” he says. That’s a question an actor must constantly ask of the character he or she is playing. And that level of self-knowledge helps him keep a level head when fame comes along to turn his world upside down, he says.

“I’ve finished a film version of Noel Coward’s play Easy Virtue, in which Colin Firth plays my dad,” he says, chuckling. “When you’re an actor, you like to imagine who might play your dad. Colin Firth. Not bad, eh?”

Narnia is actually Barnes’ second screen fairy tale. He was in last year’s Stardust. The trick to acting in such projects is ignoring the subject, not thinking it’s a fairy tale — or a religious allegory — and playing the reality of the moment, he says.

“People ask, ‘Well, you were discussing the religious context when you were on the set every day?’ ” Barnes says. “Absolutely not. That would be a dangerous thing to do. It’s not something that’s in the characters’ minds at all. You’ve just got to suspend your disbelief and be as honest as you can, within the context of that world.”

An actor has to believe he’s having a conversation with a 2-foot mouse (voiced by Eddie Izzard, who hadn’t been cast when they filmed) “and when all that’s there is a piece of wire, it kind of strains the imagination of a 25-year-old.”

Barnes admits to watching The Princess Bride before his Caspian audition (to help him find Prince Caspian’s voice, a Spanish accent not unlike the one Mandy Patinkin used in that film). He read the books when he was 8 and remembers “conjuring this magical world in my imagination,” especially Lewis’ image “of those kids walking through those fur coats (in a wardrobe) and out into the snow,” into Narnia.

He’s on board for the film for the next Narnia chronicle, The Voyage of the Dawn Treader, “my favorite of the books, when I was a boy,” Barnes says. “It’s this roving adventure, going to different lands, a book that feels like a journey out of Greek mythology, in a way.”

So he’ll be back, playing a character who is “quite an anxious figure, in this first film,” Barnes says. “I didn’t really remember that from the books, from childhood. But I had time to read the book again, you know, while I was getting my hair extensions put in.”