Keira Knightley A Divine "Duchess"

English actress Keira Knightley has been on board a pirate ship alongside Captain Jack Sparrow in "Pirates of the Caribbean: Dead Man's Chest," wandered romantic English gardens in "Atonement" and now she is a London blue blood in her latest film, "The Duchess."

With 13 films under her belt already, Knightley, 23, is Hollywood royalty in her own right.

She takes on a very powerful lead role in "The Duchess," as Georgiana Cavendish, Duchess of Devonshire, and proves that she is more than capable of portraying a strong female character.

"The Duchess," is based on Amanda Foreman's best selling biography.

"She was a very interesting woman. She was a duchess in the 18th century. She was a huge icon and big star at the time and politically very, very influential, but she was navigating her way through a very difficult marriage," Knightley told Early Show co-anchor Harry Smith.

Smith asked if she thought her character's husband, played by Ralph Fiennes, really loved her or just thought of her as a possession.

"I don't know. In his own way, I suppose. It was a really interesting relationship to look at. The dynamic between them is a very difficult one. They are two people that possibly shouldn't be together. They are from completely different worlds and they simply do not understand each other," she said.

To further the marital tension, the duchess didn't bear a male heir for a very long time, which was all he desired.

"At that point I think he was someone who saw his wife there for a social reason; she was there to produce an heir, she certainly wasn't there for companionship and she wasn't there for romance and I think she is a romantic fantasist and is faced with a harsh reality."

The duchess' dream in life was to be loved.

"At that point, for women, obviously, they didn't have the vote and they very much were the property of their fathers and their husbands. So if you happened to end up with a husband that you couldn't talk to, they didn't appreciate you, then I think that was a very, very difficult state of affairs to be in," Knightley said.

The relationship highlighted in "The Duchess" has been compared to that of Prince Charles and Princess Diana.

"I don't think I've got enough information to comment. I was 11 when Diana died and to tell you the truth I'm not aware enough of her story exactly to draw precise parallels. I think a lot of parallels could probably be drawn with quite a few women throughout history. But I think partly because emotionally, she's an incredibly sympathetic character. I think that it's impossible not to empathize with," she said.

Although Knightley admits that she is "very bad" at judging her own work, she felt incredibly fortunate to work with Fiennes, whom she considers to be "a sensational actor."

"It was wonderful to be on the set with him and watch him work and do what he does best and to try to learn something and I'm not quite sure what it was that I have learned but it was impressive to watch him," Knightley explained. "I think it was a wonderful opportunity to work with some really amazing people with very wonderful women in it. Leading roles are quite rare particularly in this size. So it was just great to get a chance to do one."