Lucifer: Princeps is a seminal study on the origins of the Lucifer mythos by Peter Grey. It is the first in a two volume work; the companion volume, Praxis, being an exposition of ritual actions, will be published in 2021. The fall of Lucifer, and that of the rebel angels who descended upon the daughters of men, comprise the foundation myth of the Western occult tradition. Lucifer: Princeps is a study of origins, a portrait of the first ancestor of witchcraft and magic. In tracing the genealogy of our patron and prince, the principles that underlie the ritual forms that have come down to us, through the grimoires and folk practices, are elucidated. The study draws on the extensive literature of history, religion and archaeology, engaging with the vital discoveries and advances of recent scholarship, which render previous works on Lucifer, however well intentioned, out of date. A concomitant exegesis of the core texts conjures the terrain and koine of the Ancient Near East, the cradle cultures and language of his nascence. Of critical importance are the effaced cultures and cults that lie behind the Old Testament polemics, viz. those of Assyria, Ugarit and Canaan, as well as Sumeria, Egypt and Greece; they provide the context that give meaning to what would otherwise be an isolated brooding figure, one who makes no sense without being encountered in the landscape. Intended to be the definitive text on Lucifer for the witch, magician and student of the grimoires, Princeps spans wingtip to wingtip from the original flood myth and legends of divine teachers to the Church Fathers, notably Augustine, Origen and Tertullian. The tales of the Garden of Eden, the Nephilim, of the fall of Helel ben Sahar and the Prince of Tyre, the nature of Azazel, and the creation of the Satan are drawn beneath the shadow of these wings into a narrative that binds Genesis and Revelation via the Enochian tradition. The story of the Serpent in the Garden and that of Lucifer are revealed to be a singular myth whose true significance had been lost and can now be restored. It illuminates the path to apotheosis, and the role of the goddess as the transforming initiatrix who bestows the crown.