The Book of Soyga, also titled Aldaraia, is a 16th-century Latin treatise on magic, one copy of which is known to have been possessed by the Elizabethan scholar John Dee. After Dee's death, the book was thought to be lost until 1994 when two manuscripts were located in the British Library (Sloane MS. 8) and the Bodleian Library (Bodley MS. 908), under the title Aldaraia sive Soyga vocor, by Dee scholar Deborah Harkness. The Sloane 8 version is also described as Tractatus Astrologico Magicus, though both versions differ only slightly.[1]