Natalie Portman Takes on a Royal Role Star dishes on seduction and her relationship with Scarlett Johansson.

Feb. 28, 2008 -- It is a tale of seduction, adultery, and murder, all played out in the garb of British royals before the backdrop of Henry VIII's Hampton Court.

These are the ingredients for Natalie Portman's latest role, playing Anne Boleyn in the royal drama "The Other Boleyn Girl." For the role, the Oscar-nominated Harvard alum became the fated Tudor queen whose grisly demise has long captured the historical imagination.

In an interview with Peter Travers for ABC News Now's "Popcorn," Portman explained that, at its most basic, "The Other Boleyn Girl" is the story of an ambitious young woman trying to "raise herself in power and position."

But the film, adapted from British novelist Philippa Gregory's best-selling fictional biography, delves deep into the personal sagas behind what Portman called "the great historical epic of Henry VIII."

Sisters 'Born to Be Rivals'

As in Gregory's novel, the central conflict unfolds around the story of two sisters and their rivalry. Anne Boleyn, the dark and calculating enchantress, finds her pursuit of the king thwarted only by the beautiful Mary Boleyn, her guileless younger sister whose fascination with the court lures her into Henry's bedroom.

Portman said she found a new set of challenges in the role of Anne Boleyn.

"The central question to trying to figure out any character is: Why do they do the things they do? How did they become the person they became?" Portman said.

This was particularly important in playing Anne, she said, because the young woman is "cruel" and "calculating."

In the novel, Gregory portrays Anne as a monomaniacal figure who tramples family and scruples to get to the throne. But Portman found complexity within the character.

"I don't necessarily believe in just bad people," Portman said. "Every once in a while there is just a bad person, but that's not necessarily an interesting character.

"It's interesting to see sort of where she comes from and to see the family at the beginning, to see the values with which she's raised," she said.

To read Peter Travers' Rolling Stone Review of "The Other Boleyn Girl," please click here.

'The Other Boleyn Girl'

First-time feature director Justin Chadwick tapped Golden Globe winner Scarlett Johansson — like Portman a former child star — to star as Anne's younger sister Mary. And though their characters vie for the same prize onscreen, Portman insisted that the two had no such rivalry off camera.

"People are dying to pit us against each other, every interview we do, they just would love for a story of a catfight to be there," she said.

On the contrary, the two young actresses connected seamlessly as both friends and co-workers.

"I signed on first and then I was really excited," Portman said. "I've admired Scarlett since 'Manny and Lo,' I've been a fan of her since we were kids. We really were a team throughout and really wanted to be together. We had the same goal of making a great movie."

A New Look at History

History has long depicted the intrigues of Henry VIII's court and the turbulence — and treachery — of the king's many failed marriages.

The film fleshes out the characters who acted out that historical drama around the king, who is played by Eric Bana.

Insisting that "all history is fiction to some degree," Portman explained that this film is "an imagination of the relationships, based on a lot of facts and truths."

From 'Star Wars' to Star Power

Portman said that in her off-screen life she is constantly searching for ways to "divert energy" — her own and that of the tabloid-fed public watching her every move — to "something that actually matters."

Most recently, that has taken the form of Portman's social work, including a new designer line of shoes made completely without animal products.

"It makes me feel a little bit better about being in a tabloid if they are like, 'Oh, and look, she's wearing her vegan shoes' and someone's like 'Oh I'm not going to kill animals for my fashion choices,'" she said.

Reflecting on her life, Portman said that she feels "very lucky." With a career ranging from the child turned hitman in "The Professional," Queen Amidala in the "Star Wars" films, to the role of the precocious Marty in "Beautiful Girls," Portman has continued to seek new ways to challenge and reinvent herself.

For now, British history has never looked so good.