Since it first appeared over 500 years ago, the Elucidation of Necromancy (Lucidarium artis Nigromantice) and the closely related Heptameron have become essential guides for individuals seeking to call on angels and other supernatural beings for help. Countless amulets and pendants have been made with its designs, and elements have repeatedly been adapted and incorporated into other manuals of ritual magic. In spite of this, neither a critical edition nor a translation has been previously published. In particular three manuscripts of Lucidarium have come to light recently, which provide a clearer and fuller ritual than the printed Heptameron. For example, they add critical instructions for making the seven angel sigils, which have become so widely known. Together they bring to life this important current of esoteric tradition, showing how it has been repeatedly adapted and used by different individuals for centuries.