Whereas Shakespeare's literary genius is universally recognized, there is also a hidden, secretive side to his work that is little known. Indeed, he used a mysterious code that figures widely in the esoteric literature of the Elizabethan and Jacobean periods. The Bard of Avon was a master of such encoding, and those who had known him continued his methods, in the Folio of 1623, as well as in his various memorials. However, Shakespeare did not invent that code. Among the many arcane authors who made use of it before him was Michel Nostradamus, the famous French prophet and savant.

As David...