Thankfully, the tagline – ‘There were three people in her marriage’ – is as far as the filmmakers are willing to push the analogy, but you can see where they’re coming from: Georgiana is a young, beautiful bride who marries into one of the country’s richest families and suffers domestic misery, while blossoming into a fashion icon and friend of the chattering classes. William is older, colder, a piercer of dreams who’s more loving to his dog than his wife and who openly introduces a mistress (Hayley Atwell) into his household. The parallels are there to play with – at a stretch, you could even pitch Georgiana’s friendship with the playwright Sheridan (Aidan McArdle) against Diana’s later flirtation with the entertainment world – but, thankfully, Dibb and co-writers Jeffrey Hatcher and Anders Thomas Jensen play no such games.
One of the strengths of ‘The Duchess’ is its intimate, unashamed embrace of its story’s here-and-now. We’re not expected to impose twenty-first century ideals of marriage on Georgiana and William, rather to empathise with their situation while considering contemporary ideas of personal freedom. It’s a theme that’s reflected in the Whig element of the story: the couple are seen to be good friends of socialite politician Charles James Fox (a reliably conspiratorial Simon McBurney), who indulges Georgiana’s forthright views on liberty. Of course, this is still costume drama, with all its attendant wigs and frocks and stately camerawork, but Dibb pays as much, if not more, attention to the private stresses of the bedroom as he does to the public rituals of dinners and balls. He’s also helped enormously by a mature, restrained portrayal from Knightley, a masterclass in passive aggression from Fiennes and a performance of tender seduction from Atwell.