The Voynich manuscript is named for Wilfrid M. Voynich, a Polish antiquarian and bookseller who obtained the manuscript in 1912. It has been carbon dated to the middle of the Fifteenth Century. Strictly speaking, it isn't written in code at all, but rather a lost language: a type of proto-Romance.
Nevertheless, its secrets have escaped cryptographers, linguists and computer scientists alike, including Alan Turing and the code breakers of Bletchley Park, the FBI, and more recently, artificial intelligence. Yet apparently they revealed themselves to the University of Bristol's Dr. Gerard Cheshire after a mere two weeks, thanks to "a combination of lateral thinking and ingenuity."
According to Dr. Cheshire, it's the only known surviving example of a proto-Romance language, a linguistic forebear of modern languages including French, Spanish, Italian and Romanian