This film is largely based on the actual life of Georgiana, Duchess of Devonshire, the renowned Georgian beauty, political and intellectual hostess, and lover of Earl Grey (yes, the one who invented the delicious tea--who knew he was such a stud!), and an ancestress of Princess Di. I've never cared much for Keira Knightly except in 'Love, Actually'--one tries to suppress the dreadful 'Pride and Predjudice'--but she is remarkably good here. Despite that, it's Ralph Finnes who runs away with the film, as Georgiana's husband the initially cold and utterly selfish Duke of Devonshire, whose glacial exterior masks a caring and rather loving nature (by the standards of the time). Dominic Cooper is clever and very studly as Mr, Grey (not yet an Earl), and Charlotte Rampling is superb as Georgiana's mother, Lady Spencer, caring and affectionate, but cold and implacable, again by the standards of the time. In fact, very few films have ever recreated the true zeitgeist of an era as well as this one. It's truly as if one had stepped back into the era.