John Dee ( 13 July 1527 - 1608 or 1609 ) was a mathematician , astronomer , astrologer , occultist , navigator , imperialist and adviser to Queen Elizabeth I of Welsh origin .
John Dee ( July 13 , 1527 - 1609 ) was a noted English mathematician , astronomer , astrologer , geographer , occultist , and consultant to Queen Elizabeth I . He also studied to alchemy , divination , and Hermetic philosophy .