The demon Asmoday appears in the grimoires Book of Incantations, The Black Books of Elverum, Hygromanteia, The Magus, Testament of Solomon, The Discoverie of Witchcraft, The Book of Spirits, The Book of the Office of Spirits, Three Books of Occult Philosophy, The Book of Abramelin, The Book of Oberon, Five Books of Mystery, Pseudomonarchia Daemonum, The Lesser Key of Solomon, Paradise Lost, and Dictionnaire Infernal
From Testament of Solomon, F. C. Conybeare edition:
"I am called Asmodeus among mortals, and my business is to plot against the newly wedded, so that they may not know one another. And I sever them utterly by many calamities, and I waste away the beauty of virgin women, and estrange their hearts."
From The Lesser Key of Solomon, Crowley/Mathers edition:
The Thirty-second Spirit is Asmoday, or Asmodai. He is a Great King, Strong, and Powerful. He appeareth with Three Heads, whereof the first is like a Bull, the second like a Man, and the third like a Ram; he hath also the tail of a Serpent, and from his mouth issue Flames of Fire. His Feet are webbed like those of a Goose. He sitteth upon an Infernal Dragon, and beareth in his hand a Lance with a Banner. He is first and choicest under the power of Amaymon, he goeth before all other. When the Exorcist hath a mind to call him, let it be abroad, and let him stand on his feet all the time of action, with his Cap or Head-dress off; for if it be on, Amaymon will deceive him and cause all his actions to be bewrayed. But as soon as the Exorcist seeth Asmoday in the shape aforesaid, he shall call him by his Name, saying: "Art thou Asmoday?" and he will not deny it, and by-and-by he will bow down unto the ground. He given the Ring of Virtues; he teacheth the Arts of Arithmetic, Astronomy, Geometry, and all handicrafts absolutely. He giveth true and full answers unto thy demands. He maketh one Invincible. He showeth the place where Treasures lie, and guardeth it. He, amongst the Legions of AMAYMON, governeth 72 Legions of Spirits Inferior. His Seal is this which thou must wear as a Lamen upon thy breast, etc.
The grouping Binsfeld's classification of demons includes this demon.
The spell To conjure up the evil spirits to force a thief to return that which he has stolen invokes this demon.
The angel Asmodel may be related to this demon.
This demon named in the historical event Loudun possessions
Illustration of Asmodaysource: archive.org
Timeline of related events
1410Lanterne of Light written (lists this demon)
1531Publication of Agrippa's Three Books of Occult Philosophy (lists this demon)
1536Publication of De praestigiis daemonum (lists this demon)
1563First known appearance of The Book of the Office of Spirits (lists this demon)
1577Book of Oberon completed (lists this demon)
1583John Dee completed his Five Books of Mystery (lists this demon)
1584Publication of The Discoverie of Witchcraft (lists this demon)
1589Binsfeld's classification of demons written (includes this demon)
1608Publication of the Book of Abramelin (lists this demon)
1634Loudun possessions (this demon named in Loudun possessions)
1641Publication of the Lesser Key of Solomon (lists this demon)
1667Publication of Paradise Lost (lists this demon)