Lists of demons occur in some of the darker grimoires, notable among them the Lemegeton or Lesser Key of Solomon. This is a collection of tracts about ritual evocation and spirit magic.
The first tract is named The Goetia and consists of a descriptive list of the seventy-two demons which were bound by King Solomon with his magic seal ring in a vessel of brass or copper, and cast into a lake (or the sea — accounts differ).
Demons are numerous. It is impossible to count the number of angels (Revelation 5:11; Hebrews 12:22; Daniel 7:10) and the fallen angels were apparently a third of all these (Revelation 12:4,9).
According to Joanes Weirus in “De praetistigiis” published in 1568, there are 7 451 926 demons, organized in 111 legions of 6666 demons and ruled by 72 princes of demons.
Fromenteau in “Le cabinet du Roy de France“ (1581) is very close to that number. An inventory supposedly made by sorcecers has yielded 7 409 127 demons and 72 princes.
According to Wier in “Pseudomania daemonum” there are 6 legions of 66 cohorts each, divided into 666 companies of 6666 individuals which comes to 1 758 640 176 demons. They are governed by an Emperor, 7 kings, 23 Dukes, 13 Marquees, 10 Counts and 11 Presidents.
Last but not least, a popular method of calculation is to multiply the number of Pythagorus by 6, i.e 1234321 x 6 = 7 405 926 demons, a number very close to Wier and Fromenteau’s conclusions.