John Dee was an English mathematician, astronomer, astrologer, teacher, occultist, and alchemist. He was the court astronomer for, and advisor to, Elizabeth I, and spent much of his time on alchemy, divination and Hermetic philosophy. As an antiquarian, he had one of the largest libraries in England at the time.
By the early 1580s, Dee was discontented with his progress in learning the secrets of nature and his diminishing influence and recognition in court circles. Failure of his ideas concerning a proposed calendar revision, colonial establishment and ambivalent results for voyages of exploration in North America had nearly brought his hopes of political patronage to an end. He subsequently began to turn energetically towards the supernatural as a means to acquire knowledge. He sought to contact spirits through the use of a "scryer" or crystal-gazer, which he thought would act as an intermediary between himself and the angels.