The Castle of Otranto, written by Horace Walpole in 1764, is considered the first Gothic novel. It tells the story of a mysterious castle and its dark secrets, focusing on themes of fate, power, and the supernatural. The narrative follows Manfred, the castle's lord, as he grapples with a prophecy that threatens his lineage. Set in a medieval backdrop, the novel features elements such as haunted castles, ominous omens, and tragic love. Its influence on the genre is profound, inspiring countless authors and works, and establishing conventions that define Gothic literature today.