The Duchess

Never as melodramatic as The Other Boleyn Girl, not as lyrical as Pride and Prejudice, The Duchess lays out a costume period drama and sticks to its guns. Based on the life of Georgiana Cavendish, Duchess of Devonshire the film stars the queen of fancy clothes Keira Knightley. Strong supporting turns by Haley Atwell and Ralph Fiennes make a perfect foil for Georgina and her loveless marriage. There's even a character who becomes Earl Grey, which I always thought was just a tea. Throw in Charlotte Rampling as the mom and it's hard to imagine a better cast.
Georgina marries as a teen and her husband expects her to raise his bastard children as well as produce him a male heir. This is 18th century equal rights, kind of like George Orwell's Animal Farm: All animals are equal but some animals are more equal than others. Atwell plays Bess Foster who at first seems to have romantic designs on Georgina but then becomes the Duke's mistress and eventually second wife. Atwell has a line describing the "rule of thumb," which is code for a law that allowed men to beat their wives with a stick as long as it was no thicker than their thumb. Something to think about next time you hear that phrase.
As you'd expect in such opulent drama the sets, locations and costumes are beyond reproach. The only part of the film that left me wanting was the actual sex. The film is rated PG-13 but the situations (it's practically a menage a trios although lopsided in the Duke's favor) could easily have embraced a harder stance. There may be parallels to current situations and people but you would need to be well versed in the lives of royals to truly make sense of such comparisons.