Although set about 200 years before the world had ever heard of Lady Diana Spencer this is the true story of another royal Spencer The Duchess of Devonshire Georgiana Spencer (Knightley) whose personal and professional life and innate sense of fashion and glamour made her all the rage in England and led her to a royal life of triumph and tragedy. Sound familiar? Based on Amanda Foreman’s award-winning biography this compelling film version introduces us to a dynamic woman whose feistiness and sense of style made her a star attraction in England’s royal circle. Smart as a whip and eventual leader of the progressive Whig party Georgiana had it all--except the one thing she wanted most the love of her husband The Duke (Ralph Fiennes) who became so obsessed with siring a son that he turned to open affairs with other women including his wife’s best friend Bess (Hayley Atwell). This humiliation and betrayal by her husband and friend leads to her own attempt at romantic happiness in a sizzling affair with the abolitionist Charles Grey (Dominic Cooper). Putting it simply Knightley has the role of a lifetime and socks it home with the kind of acting bravado she hasn’t displayed even in her best films Pride and Prejudice and last year’s Atonement. This is the kind of part an actor kills for an emotional powerhouse that allows her to run the gamut from glamour queen powerful political force tortured wife passionate lover and tragic heroine. The story of this Duchess has it all and is only enhanced by the eerie parallels to her royal descendant Princess Diana. If there is any justice Knightley will be nominated for an Oscar. She deserves it. Fiennes is equally good enjoying his finest screen outing in some time as the cold-hearted Duke who puts his own selfish goals above all else. Their scenes together are spectacularly well-acted. Atwell is demure and understated as Bess the third wheel in a very complicated relationship. She’s slyly amusing particularly in scenes she shares at the dining table with the Duke and Duchess. Cooper makes a strong impression turning up the heat as the dashing Grey especially in a smoldering love scene with Knightley. The ever-reliable Charlotte Rampling is regally comfortable in the role of Lady Spencer Georgiana’s proper mother who tries to dole out useful advice against all odds. Saul Dibb (Bullet Boy) does not have a long directing resume but you wouldn’t know it from the first-rate production he has mounted for The Duchess. Dibb recreates the privileged world of these somewhat pained characters with no detail spared. Dibb’s widescreen framing of this historic soap opera is breathtakingly beautiful to see his obvious filmmaking confidence paying off in a great looking motion picture. But it is a lot more than just pomp and circumstance. Often period dramas tend to get bogged down in spectacle and forget the human element. This is a case where moviegoers will be glued to their seats from first frame to last. It’s a whopper of a story he has adapted (with Jeffrey Hatcher and Anders Thomas Jensen) that thankfully doesn’t get lost in minutiae. Of particular note are Michael O’Connor’s costumes and Jan Archibald’s loopy hairstyle designs along with a stirring musical score supplied by Rachel Portman.