The Rohonc Codex (Hungarian pronunciation: [ˈrohont͡s]) is an illustrated manuscript book by an unknown author, with a text in an unknown language and writing system, that surfaced in Hungary in the early 19th century. The book's origin and the meaning of the text and illustrations have been investigated by many scholars and amateurs, with no definitive conclusion — although many Hungarian scholars believe that it is an 18th-century hoax.