The names Emily and Valancourt are reference to characters from the gothic romance novel Mysteries of Udolpho by Mrs. Ann Radcliffe, which was published in 1794. Emily is the heroine of the novel who goes through misfortunes after the death of her father. Valancourt is a traveller who Emily falls in love with while traveling with her father. After her father's death, Emily is under the guardianship of her aunt Madame Cheron who tries to keep Valancourt and Emily from being together and eventually marrying each other. Madame Cheron goes as far as to take Emily away with her to Italy to be rid of Valancourt. Valancourt asks Emily to marry him in secret, but Emily refuses and leaves him to go with her aunt to Italy. (Regency History)

Here is a novel cover of Anne Radcliffe's Mysteries of Udolpho: