I first read The Castle of Otranto, in college. It is reputedly the original horror story that caused Bram Stoker to create Dracula. It scared poor British boys so bad they lost sleep. I don't know about that, but I would bet money on the fact that Horace Walpole knew how a good scarey story would take the impressionable Englishmen. Walpole's friend, Thomas Grey wrote to him that his gothic horror story scared the students of Cambridge so much that it made “some of them cry a little, and all in general afraid to go to bed o’ nights.” It was 1765.
So he had this dream... A castle, a staircase, a huge armored glove in a gallery.
Then he sat down and wrote a book that he attributes to fictional character, “William Marshal, gentleman, from the Italian of Onuphro Muralto, canon of the Church of St. Nicholas, at Otranto", which Walpole claims to have found and translated from the original Italian. Dating of the of the story is placed between the first and second Crusade, sometime between 1095 A.D. and 1243 A.D., though the fictional book itself was written in the 1500's. The real book was written in English and printed in 1765.
He had a printing press... Yes, young peanut. Self publishing happened earlier then the twenty first century.
The rest is history. The medieval fantasy / gothic horror franchises had opened their doors for business.
Between the prophecy, the knights and castles, the Crusades, the zealous tyrant, the lost heir, the swooning damsels, the dying hermit, the dead knight returning to reclaim his daughter AND gigantic armor that kills people, well how can you turn that down?
My favorite part was when something terrifying happened, it always happened when the Prince of Otranto was out of the room, but many of his staff and servants saw it. They would run to him, arriving breathlessly to warn him of the danger, then start these long rambling tales. He could switch from one person to the other, trying to figure out what happened and still not understand as they would quiver, lead up to the terror and go off on tangents, etc., until he would explode in anger and finally get off his privileged butt to go see what scared them. Funniest thing. Happens three times.
Murder, mistaken identity, lost heirs, Crusaders, freed slaves, prophecies, big men with swords, saints, chases in burial vaults, secret passages, a runaway Princess, long lost parental units, a feisty priest, and a dying hermit with God on his side, not to mention the gigantic killing armor.
"Containing a Harry Potter-like array of animated portraits, supernatural adventures in vaults and cellars and astonishing, inexplicable events." --"Telegraph"
Presented as the translation of a medieval Italian text from the time of the crusades, The Castle of Otranto was the first and most influential novel of the eighteenth-century Gothic revival, and introduced several of what became its most recognizable tropes.