Originally published in Italy in 1981, the Codex Seraphinianus appears to be an encyclopedia for a world very different from Earth. It is profusely illustrated with colored-pencil drawings of fantastic beings, many of which are hybrids between categories that we generally consider wholly separate: animal-machine, vegetable-mineral. The drawings are accompanied by a ‘text’ of the encyclopedia that is written in an invented alphabet, which may or may not conceal an actual language. Neither the alphabet nor the presumed underlying language have yet been deciphered, despite the efforts of scholars and cryptographers around the world. The author of the Codex is Italian designer, architect, and artist Luigi Serafini, whose name is encoded in the book's title.
The Argentinian writer and editor Alberto Manguel, coauthor of the Dictionary of Imaginary Places, has given this near mythic account of the Codex’s origin:
“One summer afternoon in 1978, a voluminous parcel arrived in the offices of the publisher Franco Maria Ricci in Milan, where I was working as foreign-language editor. When we opened it we saw that it contained, instead of a manuscript, a large collection of illustrated pages depicting a number of strange objects and detailed but bizarre operations, each captioned in a script none of the editors recognized. The accompanying letter explained that the author, Luigi Serafini, had created an encyclopedia of an imaginary world along the lines of a medieval scientific compendium: each page precisely depicted a specific entry, and the annotations, in a nonsensical alphabet which Serafini had also invented during two long years in a small apartment in Rome, were meant to explain the illustrations’ intricacies.”
Even without a legible text, it is clear that the Codex Seraphinianus exploits the encyclopedia form not so much to assert real authenticity as to frame itself as a coherent, self-consistent, deeply elaborated exercise in world-building. The Codex may be an homage to another famous undeciphered book, the Voynich manuscript now in Yale’s Beinecke Rare Books Library. Like the Codex Seraphinianus, the hundred-odd pages of the Voynich manuscript bear a range of fantastical drawings and diagrams accompanied by a coded hand-written text. It also very probably owes at least a passing debt to Jorge Luis Borges’s variant version of the Encylopedia Brittanica in “Tlön, Uqbar, Orbis Tertius,” which Borges describes as “a substantial fragment of the complete history of an unknown planet, with its architecture and its playing cards, its mythological terrors and the sound of its dialects, its emperors and its oceans, its minerals, its birds, and its fishes, its algebra and its fire, its theological and metaphysical arguments.” And it almost certainly is linked to the speculative biology of Serafini’s fellow Italian artist and author, Leo Lionni, whose book Parallel Botany was originally published in Italian (La botanica parallela) in 1976.
 The exception is the numerals, e.g. page numbers, which have been decoded.
 Alberto Manguel, A History of Reading (New York: VIking, 1996), p. 95.
 Jorge Luis Borges, “Tlön, Uqbar, Orbis Tertius,” in Ficciones (New York: Grove Press, 1962), pp. 21-22. I discovered that Justin Taylor, cited below, made the same connection between the Codex and this passage in Borges.
Jordan Hurder, "Confronting and Collecting the Works of Luigi Serafini" (2009)
Peter Schwenger, Codex Seraphinianus, Hallucinatory Encyclopedia