Keira Knightley caught the notice of moviegoers in 2003 with major roles in two movies, the small-budget charmer 'Bend it Like Beckham' and the big-budget extravaganza 'Pirates of the Caribbean: The Curse of the Black Pearl' (opposite Johnny Depp and Orlando Bloom).

But Knightley began acting as a child and appeared in films and on television in the U.K. before being cast in George Lucas's 'Star Wars: The Phantom Menace' (1999). Hired for her resemblance to Natalie Portman, Knightley played Sabé, Queen Amidala's decoy and bodyguard.

Ever since her breakout performance in 2002's 'Bend It Like Beckham,' Keira Knightley's star has been on the rise. Now, at the tender age of 19, the British actress is front and center with the lead role of Guinevere in Jerry Bruckheimer's summer action epic, 'King Arthur.'

This version of the Arthurian legend depicts a king who is torn between his personal goals and his public sense of duty. King Arthur (played by Clive Owen) must fulfill one last mission with his Knights of the Round Table before returning to Rome a free man. With the assistance of Merlin and Guinevere, he helps change the lives of the people of Britain. As Guinevere, Knightley plays a warrior princess who helps King Arthur battle the Saxons. Her character is not the demure damsel of previous tales. This Guinevere is tougher. She's a fighter and an equal to the men of the Round Table.

"Guinevere is equally adept at manipulating Arthur to her cause as she is in the art of archery or the garrote," Knightley explained to us recently at a global press conference for the movie. Wearing a pinstripe jacket and tight black Dolce & Gabanna pants that show off her belly ring, Knightley admits the character of Guinevere would have terrified her if they had met. Sitting at a round table with the press, Knightley explains to the scribes in attendance that the role's physical challenges didn't really bother her. "I obviously trained for 'Bend It Like Beckham,' and that was soccer, but I'd sort of done that already," she says. "This was crazy, because I really had to change my body shape in a very short space of time."

She spent at least two hours a day, four days a week, with a trainer. On top of those grueling workouts, she had to attend "boot camp" with the other actors. Boxing and fighting with swords, knives and axes were all part of the regimen.

Overall, Knightley's training lasted several hours a day. She claims to have beaten the men hands down during boot camp. She was definitely the best in archery. As she says, "I was by far the best," she smiles. "I practiced with the arrows day and night."

Knightley loved being able to hit her male co-stars while they were prohibited from hitting her. Indeed, she's all about female empowerment. "Women are stronger," she says with a laugh. "We have to go through childbirth. Please! Not a question! Women are stronger."

Despite her soaring status in Hollywood, Knightley says she doesn't feel like a diva. Born in Teddington, England, she was a tomboy growing up and knew from the age of 6 that she wanted to be an actress. She has handled her new celebrity with grace. "To tell you the truth, because I'm working so much and I'm on film sets, they are like a little protective bubble, so I'm not really aware of it," she says. "I learned pretty early on never to read anything written about you. I don't know most of it and that's the way I like it kept."

She would love to experience the Hollywood scene but claims she's never been invited. She laughs and exclaims, "Send in the invitations!" Even without an invitation, Knightley is not afraid to reveal some embarrassing moments from the set of 'King Arthur.' There was a scene in which she was leading a charge and running out in front of everybody. "I yelled and ran and looked back, and there were meant to be 200 people following me," she relates. "And nobody followed me. And there was a second take in which they did actually follow me, and I fell right on my ass. It wasn't very warrior-queen-of-England-like."