One book that made the grade:
Horace Walpole: The Castle of Otranto (1764)Read about the other titles on the list.
What would become the staples of the genre were introduced in Horace Walpole's Castle of Otranto with deliberate fanfare and much hilarity. The setting is medieval and the castle itself is riddled with dungeons, cloisters, secret passages and trapdoors, precisely the sort of architectural features that would later come to symbolise, in the gothic, the human mind in its deviousness and complexity. Incest, murder, ghosts, dreams, madness, supernatural events and other elements suggestive of transgression and decay abound. The story concerns the downfall of Manfred, a tyrannical despot consumed with greed and lust who is unable to control his passions or his servants.