John Dee was a 16th-century English mathematician, astronomer, and occultist. He is best known for his work in navigation and his role as an advisor to Queen Elizabeth I. Dee was a pioneer in the study of mathematics and science during the Renaissance, and he sought to promote the use of these disciplines in England. In addition to his scientific pursuits, Dee was deeply interested in alchemy and the mystical arts. He believed in the possibility of communicating with angels and sought to uncover hidden knowledge through his studies. His extensive library and writings contributed to the fields of alchemy and esotericism.