John Dee (13 July 1527–1608 or 1609) is a noted mathematician, astronomer, astrologer, occultist, navigator, imperialist, and consultant to Queen Elizabeth I.

He devotes much of his life to the study of alchemy, divination, and Hermetic philosophy.

Dee straddles the worlds of science and magic just as they are becoming distinguishable.

One of the most learned men of his age, he had been invited to lecture on advanced algebra at the University of Paris while still in his early twenties.

Dee is an ardent promoter of mathematics and a respected astronomer, as well as a leading expert in navigation, having trained many of those who will conduct England's voyages of discovery.

In one of several tracts which Dee writes in the 1580s encouraging British exploratory expeditions in search of the Northwest Passage, he appears to have coined (or at least introduced into print) the term "British Empire."

Simultaneously with these efforts, Dee immerses himself in the worlds of magic, astrology, and Hermetic philosophy.

He devotes much time and effort in the last thirty years or so of his life to attempting to commune with angels in order to learn the universal language of creation and bring about the pre-apocalyptic unity of mankind.

A student of the Renaissance Neo-Platonism of Marsilio Ficino, Dee does not draw distinctions between his mathematical research and his investigations into Hermetic magic, angel summoning and divination.

Instead he considers all of his activities to constitute different facets of the same quest: the search for a transcendent understanding of the divine forms which underlie the visible world, which Dee calls "pure verities".

Dee's high status as a scholar also allows him to play a role in Elizabethan politics.

He serves as an occasional adviser and tutor to Elizabeth I and nurtures relationships with her ministers Francis Walsingham and William Cecil.

Dee also tutors and enjoys patronage relationships with Sir Philip Sidney, his uncle Robert Dudley, 1st Earl of Leicester, and Edward Dyer.

He also enjoys patronage from Sir Christopher Hatton.

In his lifetime Dee amasses the largest library in England and one of the largest in Europe.