Which 1764 novel is considered the first Gothic novel?

The 1764 novel considered the first Gothic novel is Horace Walpole's The Castle of Otranto. It combines medieval settings, family conflict, supernatural events, secret passages, and an atmosphere of terror that became central to Gothic fiction.

The story begins when Conrad, son of the castle's ruler Manfred, is crushed by a gigantic helmet that mysteriously falls from the sky. An ancient prophecy then threatens Manfred's family and inheritance. The novel's haunted castle, moving portraits, hidden passages, and ghostly manifestations helped establish a formula later developed by Ann Radcliffe, Matthew Lewis, Mary Shelley, and Bram Stoker.

Walpole first published the book as if it were an English translation of an old Italian manuscript. After its success, he acknowledged that he was the author in the second edition, whose subtitle was A Gothic Story. That subtitle helped give the genre its name.

Frankenstein, The Monk, and The Mysteries of Udolpho are major Gothic works, but they appeared later: Frankenstein in 1818, The Monk in 1796, and Radcliffe's novel in 1794.