An Carow Gwyn is an extensive work covering every angle and dark folkloric corner of the ancient Fairy-related beliefs of Europe and the British Isles. The first portion of the work is a sprawling, in-depth analysis of the "Fayerie Faith", the folkloric presence of the old animism and spirit-worship of ancient and pre-modern Europe, Eurasia, Britain, and Ireland. The remaining portions form a detailed modern Grimoire of practical sorcery based solely upon pre-modern principles and traditional spirit-metaphysics as they are found in the ballads and folktales of the Old World and the traditional tales and lore of witchcraft. Also included is Robin Artisson's translation of a 14th century work, "The Romance of Thomas of Erceldoune", appearing here for the first time in modern English, along with detailed notes revealing the full esoteric significance of the strange story it tells: a story of how humans relate to the Fayerie World, and what that might mean for our destiny in this world. Countless other old tales are told and analyzed for the truths and guidance they contain. An Carow Gwyn shows the Old Way of seeing and living in this world for what it truly was, where it ultimately came from, and how it still lives quietly among us. A complete philosophical treatise regarding Spiritual Ecology, and how it relates to the Old Ways, is interlaced throughout the book. Criticism of modern cultural philosophies and ideologies in light of what the Old Ways reveal, forgotten histories underlying many of our cultural stories and myths, and the hidden laws and techniques behind basic and advanced historical works of sorcery (all of which are explained in exacting detail) are carefully brought together in this substantial and paradigm-shifting work. An Carow Gwyn contains over 60 illustrations and diagrams, and gives historical (and accessible) spells and workings from the Classical to the Elizabethan eras for seeking oracles through dreams, swaying the spirits of forests and graveyards, protection and uncrossing, opening doorways into spiritual regions, and even the supreme act of disassociating from bodily experience and traveling in the Unseen world.