When The Mysteries of Udolpho was published in 1794, Jane Austen was nineteen years old. She was actively writing (much of what she produced during this time period is referred to as her "Juvenilia") and interested in the literary world around her. It is possible that Austen was already writing a novel that satirized the Gothic fiction that was so popular at this time, but by 1798 or 1799, she had completed a manuscript that actively played with Gothic conventions, and contained direct references to The Mysteries of Udolpho. This manuscript was initially titled Susan, and in 1803, Austen sold it to a publisher, who ultimately chose to delay publication. Between 1816 and 1817, Austen made changes to the manuscript, including changing the name of the protagonist (from Susan to Catherine). She died in July 1817, and a few months later, her brother Henry finally arranged for the publication of the novel, which appeared as Northanger Abbey in December 1817.
The young protagonist of Northanger Abbey, Catherine Morland, is an avid reader. After befriending siblings Henry and Eleanor Tilney, she goes to stay with them at their English country home, which gives the novel its title. Gothic novels often feature a significant building as a key feature of their plot, which is sometimes also referenced in the title (for example, The Mysteries of Udolpho, or Horace Walpole's Gothic novel The Castle of Otranto). Austen plays with this convention, and the reference to an abbey (a type of monastery) also hints at the Catholic elements often present in Gothic fiction. However, in England, many country estates owned by private families have the name of "Abbey" (for example, the popular television program Downton Abbey) because these buildings began as monasteries when England was a Catholic country, but were seized by the English Crown during the Reformation in the 16th century, and eventually passed along to members of the nobility as private residences.
Because of her avid reading, Catherine assumes that Northanger Abbey will be a mysterious and dramatic place, even though it is completely ordinary. She is so set on this assumption that she becomes unreasonably suspicious of General Tilney, the father of her friends. Upon learning that Mrs. Tilney died several years ago, and deciding that the General doesn't seem to mourn the loss of his wife, she becomes suspicious that he may have murdered her. When these suspicions come to light, Henry Tilney scolds Catherine for having an overactive imagination and harboring outlandish suspicions. However, the General does turn out to be a stern and cold man, who tries to end the burgeoning relationship between Catherine and his son when he learns that she is not as wealthy as he had initially thought.
Catherine's suspicions of General Tilney potentially killing or imprisoning his wife have clear parallels to the plot of Udolpho, wherein Emily suspects that Montoni may have killed his wife, and where it is eventually revealed that the Marquis de Villefort did poison his wife. Before she goes to Northanger Abbey, Catherine is eagerly reading Radcliffe's novel, and makes comments such as "Oh! I am delighted with the book! I should like to spend my whole life in reading it" and "while I have Udolpho to read, I feel as if nobody could make me miserable." While Catherine at first assumes that Henry Tilney will not have read or enjoyed the novel, since he is a very intelligent and sensible person, he openly praises it, and celebrates the pleasure of reading novels in general. Henry's perspective provides an important counterpoint to Catherine's experience: while her reading is somewhat destructive, as it leads her imagination to run away with her, more grounded readers can take deep pleasure in devouring the novel.