The prophetic books of the 18th-century English poet and artist William Blake are a series of lengthy, interrelated poetic works drawing upon Blake's own personal mythology. They have been described 20th-century critic Northrop Frye as forming "what is in proportion to its merits the least read body of poetry in the English language".[1] While Blake worked as a commercial illustrator, these books were ones that he produced, with his own engravings, as an extended and largely private project.