The most significant surviving Latin text on magic, the Summa Sacre Magice is now available in English for the first time ever. Dating from 1346, the Summa Sacre Magice by Berengarius Ganelli provides the foundation for many grimoires and contains practical magic that has been lost from later manuscripts. Owned by Johannes Trithemius and Dr. John Dee, this text is the root of Shemhamphorash, Solomonic, and Enochian magic. Translated into English by Dr. Stephen Skinner and Daniel Clark, this volume contains the third and fourth books. The Summa Sacre Magice is a foundational grimoire. Unlike most early grimoires, which often lack the author's name and date, this manuscript proudly includes both. Its ancient origins and its wealth of lost knowledge make it an invaluable resource. Later grimoires failed to capture much of the detailed richness found in this text, confirming its status as the most significant Latin text on magic that has survived. This work stands as the most comprehensive overview of Latin mediaeval magic that has endured for almost 700 years. Among its many secrets are some of the earliest details of angelic invocations. These are intricately woven into the tapestry of the practical and sacred magical tradition. The transmission of this knowledge passed through four main teachers: from the 12th century Solomon (not the famous Biblical king) to Toz the Greek magician, then to Honorius, the author of Liber Juratus (13th century), and finally to Berengarius Ganelli (14th century).