This is the first book to offer a unified approach to invoking all classes of angels: from the mighty Archangels and Thrones to the angels of the Shemhamphorash, the ruling angels of the decans, and even the lesser messengers and servitors. Through clear instruction and innovative ritual techniques, Liber Artis Archaeomancy empowers intermediate and advanced practitioners to master a new level of spirit work. With his signature clarity and depth, Frater Barrabbas provides everything needed to work this compelling system of magic.