Natalie Portman is disarmingly self-effacing for an Oscar winner with a good chance to net a second golden statue next month. “I usually see a movie once when it comes out at the premiere and then never see it again,” she told the Guardian last summer. “Usually I cringe through the premiere and hate everything I do. The less I’m in a movie, the more I like it.”

If ever Portman is in need of a confidence boost, she’d do well to glance over the ecstatic reviews lavished upon Jackie, her latest film. For taking on arguably the biggest challenge of her career by playing Jacqueline Kennedy Onassis, one of the most enigmatic and beloved women in American history, Portman has received plaudits so complimentary they rival those she got for her Oscar-winning performance as a doomed ballerina in Black Swan.

Variety praised Portman’s portrayal as “complex” and “meticulously shaded”. “To watch Portman’s every move is to not only watch history being recreated, but to also witness history being made,” wrote Barry Hertz of the Globe and Mail. “No one will ever be able to touch this role again. Or, at least, no one should.”

Portman doesn’t much resemble the former First Lady; she does however nail her breathy and docile-sounding voice, without letting the affectations get the better of her. Tom Hanks, speaking at the Palm Springs film festival last week, reckons it’s Portman’s “unknowable mystery” that made her “the only actor” to star in director Pablo Larraín’s intimate portrait.

Hanks is right. As written by Noah Oppenheim, Kennedy Onassis is presented as a fascinating blend of contradictions: testy with press, vulnerable when prodded, fiery when challenged and timid when faced with the decorum of the White House.

Likewise, Portman is something of an enigma. In profiles, she can come across as guarded and wary. During an interview with the Hollywood Reporter, timed to coincide with the Cannes film festival premiere of her directorial debut, A Tale of Love and Darkness, Portman allegedly recorded the entire conversation on her phone to “make sure that everyone’s accurate”, a rare move by celebrities. Yet in the same feature, her Black Swan director Darren Aronofsky described Portman as “very sincere and fun”. “She really enjoys life,” he said.

Natalie Portman in her Oscar-winning role as an ill-fated ballerina in Black Swan. Photograph: Niko Tavernise/AP

Survey Portman’s career and life story, however, and one certain quality emerges: she’s a remarkably tenacious figure. Born in Israel in 1981 to an Israeli father and an American mother, Portman moved with her family to the US when she was three. At the age of 10, a Revlon scout spotted her at a pizza place near her home in Jericho, Long Island, and asked if she was interested in becoming a model. At such a young age, she was already headstrong and told the stranger she would rather try acting.

“I was definitely different from the other kids,” she said in 2005. “I was more ambitious, I knew what I liked and what I wanted, and I worked really hard. I was a very serious kid.” Two years later, she auditioned for the role of Mathilda, the street-smart orphan who befriends a middle-aged hitman in Luc Besson’s Léon: The Professional, and secured the part, making her feature film debut.

For the next several years, Portman stuck to similarly mature fare, playing a smitten youngster pining for a grown man in Ted Demme’s Beautiful Girls, going up against Al Pacino as his troubled daughter in Heat and charming her way through Woody Allen’s musical romance Everyone Says I Love You. On Broadway, she made her debut in the title role of The Diary of Anne Frank, a performance that is said to have taken a toll on the young performer, whose great-grandparents were killed in Auschwitz.

It wasn’t until signing on to George Lucas’s Star Wars prequel trilogy in 1999 that Portman appeared in projects skewed more closely to her own age group. Embarking on the role of Padmé Amidala, the mother of Luke Skywalker and Princess Leia, gave Portman her biggest audience yet, a factor that would go to the head of most young actors. Portman appeared unfazed, famously missing the New York premiere of Star Wars: Episode 1 – The Phantom Menace to revise for her high-school finals.

Natalia Portman in her role as Padmé Amidala in Star Wars Episode II – Attack of the Clones. Photograph: HO/REUTERS

When the negative reviews for her first stab at a major blockbuster hit, Portman left Hollywood for the world of academia (she told the New York Post: “I don’t care if [college] ruins my career, I’d rather be smart than a movie star”), completing a degree in psychology at Harvard and co-writing two research papers published in scientific journals.

Portman largely took a break from acting to focus on her studies, only appearing on screen in the Star Wars sequels during her four years at Harvard and on stage in a New York Public Theater production of Chekhov’s The Seagull alongside Meryl Streep, Kevin Kline and Philip Seymour Hoffman, directed by Mike Nichols.

She credits Nichols, who has since died, for giving her a lift following the critical bashing she received for her stiff contributions to Star Wars. (Her co-stars Liam Neeson, Samuel L Jackson and Ewan McGregor didn’t fare much better with the critics, but they were more established than Portman at the time.)

“Star Wars had come out… and everyone thought I was a horrible actress,” Portman told New York Magazine in 2014. “I was in the biggest-grossing movie of the decade and no director wanted to work with me. Mike wrote a letter to Anthony Minghella and said, ‘Put her in Cold Mountain, I vouch for her.’”

His encouragement did the job. After playing a small but pivotal part in Minghella’s Civil War drama, Portman returned to the demanding roles with which she first made her name, shaving her head to embody a freedom fighter in V for Vendetta, going full-blown arthouse for Wong Kar Wai’s English language debut My Blueberry Nights and earning her first Oscar nomination for playing a stripper in Nichols’s ensemble drama Closer.

Then came Black Swan, which not only cemented Portman’s status as one of the most acclaimed performers of her generation, but also one of the most bankable after the low-budget thriller took nearly $330m (£270m) worldwide. It also introduced Portman to her husband, choreographer Benjamin Millepied, who was working on the film. The two have a son together named Aleph (after the first letter of the Hebrew alphabet). And the family relocated to Paris for a short while after Millepied secured the post of director of dance at the Paris Opera Ballet; they returned to Los Angeles last summer.

A Tale of Love and Darkness, her Hebrew-language adaptation of Israeli writer Amos Oz’s autobiographical novel of the same name, earned mixed reviews. But following her Star Wars experience, Portman has learned to brush off rebukes by simply avoiding all reviews that cite her name.

“It’s inhibiting to hear bad things about yourself,” she explained. “It makes you afraid and you can’t be afraid when you work. As an artist you have to be very emotionally ready, emotionally connected to everything but then, as a public figure, you have to have such a thick skin. People will say such harsh things. You need to be vulnerable for your work, but you also need to be tough as nails just to keep up, and that combination is really hard to maintain.”

THE PORTMAN FILE

Born Natalie Hershlag, 9 June 1981, in Jerusalem, to Avner Hershlag, an Israeli doctor, and Shelley Stevens, an American artist from Cincinnati, Ohio.

Best of times She gave birth to her son, Aleph Portman-Millepied, on 14 June 2011, shortly after winning her Oscar for Black Swan. Her son’s father, husband Benjamin Millepied, worked as a choreographer on the film.

Worst of times Portman struggled with being sexualised as a child after appearing in Léon: The Professional. “I had a bad experience when Léon first came out,” she told the Independent. “In hindsight, I’m really proud of that film though at the time it was unnerving to find myself being suddenly looked upon as a sexual object when I was still only 12.”

What they say Kenneth Branagh gushed to the Hollywood Reporter of Portman’s “formidable and occasionally forbidding kind of concentration”. “She certainly has a ticklish sense of humour,” he added.

What she says “It’s always fun getting to visit a movie set as a tourist. When you go and it’s your job and you go every day, you get a little immune to how magical it is. To experience it as a tourist just makes it magic again.”