John Dee (1527-1609) has emerged as one of the most influential figures in the intellectual history of Tudor England. Though best known in his own time as a mathematician, he had a host of other interests (including navigation, astrology and astronomy, cabbala, alchemy, paracelsian medicine, and Welsh history) and was one of the first scholars to advocate collecting manuscripts from the dissolved monastic libraries. Indeed his own library was perhaps the largest assembled in England by one man before 1600. This study, which includes a facsimile of the detailed catalogue of 1583, recounts for the first time the growth of Dee's library, the raid made upon it during his absence in Poland, and its dispersal after his death. The book also describes the location of his surviving books and manuscripts.