William Cavendish

William Cavendish (better known as The Fifth Duke of Devonshire) is a real life British aristocrat and is what can be considered the main antagonist of the 2008 film The Duchess.

History
In the film, Cavendish is portrayed as the old, bitter husband of the duchess protagonist, Georgiana. He is also depicted as a vicious adulterer who cheats on his wife constantly. These ongoing affairs led to a relationship between Lady Bess, Georginana's closet friend, crushing the duchess. The main reason behind this affair, however, is so the Duke can get Bess' three sons and use them as trustful heirs in the future.

Georgiana then, in a fit of anger, began her first affair with later prime minister Charles Grey, an action in which the Duke disapprove by raping his own wife. After this event led to a son from the Duke and a son from Grey, William forces the duchess to end the relationship by threatening to end Grey's political career and forbid her from seeing her children. With the ending of the relationship, the Duke, Bess, and Georgiana live their lives in peace from years to come, as the children were given to the Grey's.