Horace Walpole published The Castle of Otranto on December 24, 1764, through his private press at Strawberry Hill, his Gothic Revival estate in Twickenham, England. The first edition appeared under the pseudonym William Marshal, purporting to be a translation of a 16th-century Italian manuscript. Walpole stated the story originated from a nightmare. The novel combined supernatural elements from medieval romance with 18th-century realist fiction, employing hidden identities, secret passages, and spectral apparitions. Subsequent writers including Ann Radcliffe, Matthew Lewis, and Mary Shelley adopted and expanded upon these conventions.