‘The Duchess’ herself, Keira Knightley

As no one who has seen “The Duchess” has failed to observe, there are certain parallels between Georgiana, the Duchess of Devonshire, and Keira Knightley, the actress who plays her. The wife of the influential Duke William Cavendish, Georgiana was greeted by throngs of admirers everywhere she went, her actions instant fodder for the nation’s gossip columns. She exploited her public profile to lend support to the liberal Whig party, and her extravagant fashions, which echoed those of her friend Marie Antoinette, were rapidly copied in high society. She even managed to change the way people spoke, creating a fashion for her husband’s “Cavendish drawl,” which rendered her name as “Georgaina.” She was, in short, the 18th century equivalent of a movie star.

It would be natural to assume Knightley was drawn to the role out of empathy for Georgiana’s plight, that she saw in her attempt to reconcile her public persona with her private self some echo of the modern celebrity’s dilemma. But when the subject comes up, Knightley can barely stifle a yawn.

“I didn’t look at her and go, ‘Ooh, I get followed by people and I get written about, therefore you’re interesting,’ ” Knightley said at the Toronto Film Festival in September. “I sort of thought, weirdly, that was the least interesting part of it. It’s interesting that the cult of celebrity, which I thought was a modern phenomenon, was going on 300 years ago and we haven’t moved on from it. But I don’t look for parallels with myself.”

Knightley approaches her public persona as she would any other role. At premieres and public appearances, she is as much in character as when she is on the set. In interviews, she plays a different role: the serious actor who doesn’t take herself too seriously. Her answers are laced with offhand profanities, as if to forestall any confusion with the posh period damsels she often plays. In Toronto, she was dressed all in black, the monochrome outfit setting off her pale, even skin.

“I think complexity attracts me,” she says. “I look for characters that aren’t two-dimensional, that aren’t simply good or bad, that are sometimes really annoying, that contradict themselves, that are occasionally hypocritical, all the rest of it.”

A liberated woman in a patriarchal era, Georgiana is a study in contradiction. She is strong-willed, even obstinate (a Knightley trademark), but also eager to please, particularly where her husband, played by Ralph Fiennes, is concerned. Their marriage, never a love match, grew increasingly frosty over the years as Georgiana failed what was considered her primary duty: giving birth to a male heir. Amanda Foreman’s biography relates an incident in which Georgiana plops coquettishly into her husband’s lap and he pushes her onto the floor.

“With this character in particular, it was somebody who has got this huge public persona and is hugely influential and a huge fashion icon, and is desperate for a kind of huge attention and is very comfortable in crowds, and yet is so achingly lonely and in this stifling marriage, and so vulnerable,” Knightley says. “I suppose I loved the juxtaposition of those things. I thought she was an incredibly sympathetic person.”

Although the age difference between Knightley and Fiennes is far greater than that between Georgiana and her husband, the disparity furthers the movie’s emphasis on the remoteness of their relationship.

While Georgiana enters the marriage with her girlish illusions intact, the duke shows more tenderness toward his dogs than he does to his wife. Although he descends to outright cruelty, he is at first merely crushingly indifferent, utterly uninterested in his wife outside the execution of her marital duties.

“Normally, when you play a married couple, it’s about trying to get the familiarity, it’s about trying to look physically comfortable,” Knightley says. “Within this, you’re playing against any kind of comfort whatsoever.”

The duke is one of Fiennes’ least stylized turns, due in part to Knightley’s unaffected ease. “She plays the social vivacity and energy, but she’s totally natural,” Fiennes says. “It’s a wonderful performance.”

Although the filmmakers attempted to replicate Georgiana’s legendary excessive wardrobe, some changes had to be made to accommodate the differences between the actress and her subject.

“We did try a few dresses that were as accurate as you could be from a Reynolds painting, which was probably quite different from the original anyway,” Knightley says. “It just didn’t work. I didn’t have the bosom to carry off the amount of ruffles that she actually did.”

Adams is a freelance writer.

calendar@latimes.com