Warning : the following documents deal with magic and should not be used without proper care and deep knowledge of this art.
The word grimoire is from the Old French grammaire, or grammar. Latin "grammars" (books on Latin syntax and diction) were considered in the Middle Ages as books of basic instruction.
Today, a grimoire is considered as a book of magical knowledge, with instructions for its use to achieve certain ends. Most grimoires were written between the late-medieval period and the 18th century and are associated with ceremonial or ritual magick.
They contain various magical formulas or symbols such as astrological correspondences, incantations and ritual instructions for working with angels and conjuring spirits and demons as well as directions on casting charms and spells, on mixing medicines, and making talismans. A grimoire should not be used as a 'recipe book'.
To understand the real content, one must delve into the life and times of the magicians who wrote them and decipher the symbols that were used to hide the real secrets.
Most grimoires are made of a strange blending of Jewish, Roman and Christian formula and filled with biblical references and prayers to angels or God. Although the magicians who wtore them found inspiration in Pagan and Islamic texts, they often relied on Christian magical traditions going back as far as the first century.
Most powerful invocations are inspired from the words of Jesus: "I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in Heaven..." Those grimoires who are associated with black magic and focus on the art to submit demons belong to the Goetia.
These books gave birth to a great number of secondary grimoires that were widely distributed in during the XIXth century thanks to the development of the printing industry.
The most well-know are “Le Dragon Rouge” (The red dragon), “La Poule Noire” (The black chicken), “The Greater Etteila” and “Le Grand Albert” et “Le Petit Albert” (the greater and the lesser Albert). They are full of stupidities such as “how to make girls dance without shirts”.
In the late 19th century, several of the earliest-known Grimoires (including the Abramelin text and the Keys of Solomon) were reclaimed by neo-Masonic magical organizations such as the Hermetic Order of the Golden Dawn and the Ordo Templi Orientis.
Aleister Crowley, who was part of both groups, synthetized the occult knowledge and influenced a number of modern movements, including Wicca, Satanism, and Chaos Magic.
A cottage industry has existed since the 19th century in selling false or carelessly-translated grimoires (many original texts are in French or Latin, and are quite rare), although faithful editions are available for grimoires.net.
The Necromicon also known as Al Azif or the whispers of demons was supposed to have been written by the black wizard Abdul Al-Hazred who lived in Yemen 700 AC. It became famous after horror novelist HP Lovercraft used it as a prop in not fewer than 18 of his stories
Today most agree that The Necromicon is a compilation of spells, recipes and other texts taken from older grimoires as The Key of Salomon, the Ars Goetia, or the Kitab al Uhud from Araby which were among the famous magic library of Assurbinapal.
More about the Necronomicon
Other volumes, less well known, but just as ominous in content, are De Vermis Mysteriis (Mysteries of the Worm), by Ludvig Prinn and Unaussprechlichen Kultin (Nameless Cults) by von Junzt. The authors of the two volumes both met terrible fates, as did Al-Hazred. Ludvig Prinn was burned at the stake, and von Junzt was strangled by a hideous monster when he was alone in a locked room.