A serious star at 18, Natalie Portman is sweet, smart, and about to ride the rocket of the Star Wars machine.

When Natalie Portman transforms herself on celluloid from New York teenager into intergalactic ruler of a small planet, her metamorphosis is sheer perfection. Completely gone is the sweetly self-conscious high school girl. In her place is a young Queen, so confident, so dazzling and regal, it's almost impossible to reconcile the two.

It's pure magic up on the screen, but how did Portman, 18, make the tricky journey so seamless? She smiles broadly, raises an eyebrow, then divulges the secret. No, she confesses, she did not use a modern day monarch or a historic ruler as the touchstone for her portrayal of Queen Amidala, ruler of the planet Naboo, future bride of Darth Vader, and mother of Princess Leia and Luke Skywalker in this year's most talked about pop culture event, Star Wars Episode 1--The Phantom Menace. Truth is, she whispers, she found Amidala's voice and carriage in the last place you might think--the golden era of Hollywood. Specifically, in Lauren Bacall.

"[The director] George Lucas, wanted me to find a different voice, so we tried a little Lauren Bacall, with her mix of regal and deep, and then we mixed it up with other accents," Portman says, explaining that her interpretation of Bacall's husky tones sealed the deal. "And once I had the voice down, with the make-up and costumes, I would go entirely into the young Queen's character."

While using Bacall as an influence might seem to come from left field, there is a beautiful symmetry to her choice. Both Bacall and Portman have a luminiscent beauty the camera lives for. Both found fame as teenagers; Bacall was an icon at 19, in To Have and Have Not, while Portman is about to assume mythic status thanks to a cult called Star Wars.

And while Bacall had the irresistible Bogie, Portman actually goes one better. She has Obi-Wan Kenobi.

Sitting in the lobby of New York's so cool-it's hot Mercer Hotel, clad in checked pants, a green jacket, with no make-up and tousled hair, Portman is a study in contrasts. Few walking by the actress register that sitting in front of them is the woman who has inspired an action figure, fanatical web sites, and adults worldwide to camp out for tickets to see her strut her stuff. And, frankly, that's just the way Portman likes it. Attention embarrasses her. She won't focus on herself, and it's not false modesty either. She doesn't hang with a Hollywood pack, preferring to live quietly with her parents in the Long Island suburbs. She makes two movies a year and no more. School, friends and family always come first. A straight-A student, she has been accepted to Ivy League colleges she will not name. She is genuinely grounded and polite in a way most teens, let alone actresses in the white heat of fame, are not.

And in conversation she is attentive and whip smart, only veering off course to blush when talking about boys and clothes. No wonder directors consider her the one to watch, the It girl of her generation.

Portman, an only child, was born in Jerusalem to an Israeli doctor father and an American artist mother who moved with her to the US when she was three. She tells you she was always performing, with her young heart set on becoming a Broadway hoofer: "I was really into dancing, taking six classes a week, and my real dream was to be in a Broadway show." But fate intervened one night in a pizza parlour near her home, when a Revlon scout saw the 11-year-old Portman and asked if she would consider modelling. Amazingly, she said no, countering that she was interested in performing. The conversation led to an agent, auditions and the role as the assassin's companion in The Professional directed by Luc Besson.

"I went onto that film and I didn't know what I was doing--but I was 11, and it was before the whole pre-teen self doubt set in. I was at that stage where I was completely unselfconscious, free and open, and it was really fun. I trusted Luc, and, luckily, my first experience was with such a great director. Luc really guided me."

When the film opened, her beauty and intelligence burned through the screen, sending directors into overdrive. From that one role, Portman and Hollywood were bitten and she began building a resume unlike anything her peers could emulate. While they were busy making schlock-horror or prom-night flicks, Portman clocked up screen time opposite Oscar-winners Timothy Hutton in Beautiful Girls, Jack Nicholson in Mars Attacks!, and Al Pacino in Heat.

"Ninety per cent of how you learn is watching great people. When you are surrounded by good actors it lifts your performance," she says of working with the A-list. But she also makes wise, against the grain choices. Last year, she did nine months on Broadway as Anne, in The Diary of Anne Frank, while her contemporaries were busy screaming about what they did last summer.

"I didn't stay away from those teen movies consciously," she says. "I think it's more I am hard to place in those films because I don't fit the stereotypical parts; I am not the nerd, nor the cheerleader."

The simple truth, she says, is the teen movies they are churning out like sausages now are not creative enough to interest her. Not like the Star Wars prequel which Portman jumped at when approached by George Lucas. Forget Nicholson and Pacino, this month she goes head to head with Liam Neeson, Ewan McGregor and a galaxy of eye-popping special effects in the most anticipated film of the decade. (One wag suggested Menace will sink Titanic ten times over).

"I had never seen the Star Wars films," she admits. "I have cousins and friends who are Star Wars freaks, so I had an understanding of how important the films are to the culture, but, honestly, not like I do now."

And boy does she now. Today she can see the fans obsessing on the Internet and outside movie theatres, and it takes her breath away. "I had no idea all this attention would happen, but the thing that comforts me is that it is all about the movie, not about a single component of it."

Although her career trajectory has been reasonably non-commercial, Portman says she really wanted the role, wanted to be part of Star Wars history. "I have never done a really commercial movie and it's fun to be part of something that people really love. And this is such a beautiful film, so artistic."

Star Wars Episode 1--The Phantom Menace begins 30 years before the original Star Wars, when Qui-Gon Jinn (Neeson) and his apprentice Obi-Wan Kenobi (McGregor) arrive on the planet Naboo which is embroiled in a conflict with the Trade Federation. The Jedi transports Queen Amidala away to safety, with the Federation and a Dark Lord in hot pursuit.

As the only female lead in the film (and she is committed to making two more), Portman knows her life is going to change irrevocably, that Amidala will become part of the lexicon along with R2-D2, Princess Leia and Luke Skywalker. But not only is Portman ready for it, she welcomes it. "I think it's great if it happens. Queen Amidala is a solid female character. She is a young ruler, strong, peaceful and protective of her people. I am happy she will be a role model for young girls."

Despite the attendant chaos right now, Portman is remarkably laid-back about both her life on the Hollywood merry-go-round and her long-term goals. She is not putting off university, despite myriad acting offers rolling in. "I come from a long line of academics. Education is number one in my family." Nor does she know if she wants to be an actress forever. She can just as animated whether she is talking about maths (yes, maths), science or movies as a career.

"I am a competitive person and I am ambitious, but I am not crazed by this business," she says. "It has very alluring aspects that would probably make it very difficult for me to give up completely, but I am not a person who needs to work constantly."

Ask Portman about boyfriends and you are met with a sweet smile that says she is not about to go there. You can't blame her. Which 18-year-old girl would? Ask about fashion, however, and her face lights up.

"Mmm, I like clothes a lot," she says, explaining that a Helmut Lang Jeans jacket is practically her uniform. She also admits to a passion for Gucci and Prada (like all actresses, she is offered clothes for events), but goes on to explain that as a committed vegetarian, she will not wear leather or fur. It's time for Portman to leave, and she announces excitedly that she is heading for a record store to buy music by a band I have never heard of. It's whan you know for certain this about-to-be phenomenon really is still a sweet suburban teen, and Hollywood hype hasn't ruined her a bit.

"People often ask if I feel like I gave up my childhood for movies, but I don't see it that way," she says. "I go to parties, I see my friends, I live a normal life, and I make films. I feel so fortunate. I haven't lost anything. If anything, it's like I have had the double life."