John Dee, an English astrologer, born in London, July 13, 1527, died at Mortlake in 1608. He was educated at St. John's college, Cambridge, and attained much proficiency in science. After a short tour in Holland he was elected fellow of Trinity college, and in 1548 took his degree of master of arts. Incurring the suspicion of being a conjurer, he repaired to the continent, resided two years at the university of Louvain, and visited France, spending some time at the college of Rheims, where he gave lectures on mathematical theorems, elaborated into metaphysical and astrological dogmas, which were received with great applause. On his return to England in 1551, Edward VI. conferred on him a pension of 100 crowns, which he afterward relinquished for the rectory of Upton-on-Severn. Shortly after the accession of Mary he was accused of practising against the queen's life by enchantment, and was subjected to a protracted trial and long imprisonment, but released in 1555. On Elizabeth's accession be was introduced to her, and was requested to name a propitious day for the coronation. In 1564 he returned to the continent, ostensibly to present the emperor Maximilian with a copy of a work he had dedicated to him, but probably as a secret agent of the English government.

When in 1571 he fell dangerously ill abroad, the queen sent two of her own physicians to his relief. After his return he settled at Mortlake, Surrey, where he calculated horoscopes and nativities. In 1576 the people in the neighborhood attacked his house, and he barely escaped with his life, his library, furniture, and apparatus being all destroyed. He was sent abroad again in 1578 to consult with German physicians touching Elizabeth's health, and probably also for some secret political object. In 1581 he made the acquaintance of Edward Kelly, an apothecary whose ears had been cropped for forgery. He pretended to be as sincere a devotee to magic as was Dee himself; and with his assistance spirits were raised and information obtained by use of a crystal or magic mirror, in which, after invocation, responses were granted to their inquiries. In 1583 they made the acquaintance of Albert Laski, a Polish nobleman, and accompanied him abroad. They exhibited before the emperor at Prague, and resided there for a time, asserting that they had the art of transmuting metals, enabling them to live in considerable splendor. At Prague they separated.

Dee returned to England, and was appointed on Dec. 8, 1594, chancellor of St. Paul's cathedral, and in the following year warden of Manchester college, which he left in 1602 or 1604 to return to his old residence near London. A catalogue of his printed and published writings is contained in his "Compendious Rehearsal of his Life and Studies," prepared in 1592, on the appointment of a commission by Elizabeth to inquire into his circumstances. His diary was printed in 1842 by the Camden society, together with the catalogue of his library of MSS., made before the pillage of his house by the mob, and containing the titles of several mediaeval works, not now known to be in existence. Dee's " Relation of what passed for many years between him and some Spirits," edited by Casaubon, appeared in London in 1659. One of his magic mirrors is in the British museum.