The film tells the true life story of Georgiana, Duchess of Devonshire, who was the great-great-great-great aunt of Diana, Princess of Wales.

In the film Knightley plays anaristocratic woman that is trapped in a marriage to a man who is in love with his mistress. It is this storyline that mimics the experiences of Princess Diana, who married Prince Charles only to discover that he was continuing a long-standing clandestine relationship with another woman.

Even the film’s tagline, "There were three people in her marriage", suggests a link to Diana’s story, as it bears a remarkable similarity to the words the princess used to describe her own situation in a highly candid1995 television interview.

Speaking to the BBC, Keira Knightley was quick to play down the similarities in the stories, saying her character was "an interesting enough person to warrant a film completely about her without comparisons".

In fact the 23-year-old actress claims not to remember the story of Prince Charles and Princess Diana’s doomed marriage.

"I was 11 when Diana died, so I don’t really know what the actual story is so I don’t feel I can comment on the parallels," Knightley scoldedreporters at a recent press conference.

Whether the Diana connection exists or not, The Duchess provides a fascinating insight into personal relationships in a society where divorcewas taboo.

The film is also a visual feast as the architecture and fashions of 18th Century England are painstakingly recreated down to the smallest detail.