The Sigillum Dei (seal of God, or signum dei vivi, symbol of the living God, called by John Dee the Sigillum Dei Aemeth) was a late Middle Ages magical diagram, composed of two circles, a Pentagram, and three Heptagons, and is labeled with the name of God and his angels. It was an Amulet (amuletum) with the magical function that, according to one of the oldest sources (Liber iuratus), allowed the initiated magician to have power over all creatures except Archangels, but usually only reserved for those who can achieve the blessed vision of God and angels (beatific visionary).
Probably the oldest known description and image of the Sigillum Dei is the 14th Century Liber iuratus (also Liber sacratus, Liber sacer sive iuratus, or Sworn Booke.)  attributed to Honorius, son of Euclid., This may have been produced in the late 13th century, but likely not before the time of Pope John XXII. (1316–1334) .
The description of the seal in the Liber iuratus begins with the dimensions of the circle surrounding the outside in relation to common symbol figures of the Christian tradition 
"make first a circle whose diameter is three fingers, because of the three cross-nails of the Lord, or five fingers because of the five wounds of Christ, or seven for the seven sacraments, or nine for the nine orders of angels, but usually five fingers will suffuce. Then make a second within this circle, let it be a distance from the first two grains because of the two Tablets of the Law of Moses, or three grains because of the persons of the Trinity."
The so created circular band will be at an apex of a small cross and from this starting point proceed from left to right 72 Latin letters, which vary in tradition (MS Sloane 3853: h, t, o, e, x, o, r, a, b, a, s, la, y, q, c, i, y, s, t, a, l, g, a, a, o, n, o, s, v, l, a, r, y, c, e, k, s, p, f, y, o, m, e, n, e, a, u, a, r, e, l, a, t, e, d, a, t, o, n, o, n, a, o, y, l, e, p, o, t, m, a), the sum forming the Shemhamephorasch, the ineffable name of God ("magnum nomen Domini Semenphoras licterarum 72"), showing a clear link to Jewish tradition.
Next to the circular band is a pentagram, which focuses on a Greek Tau, this is surrounded by the five letters of the name of god "El" and "Ely", and five other pairs of letters (lx , al, a, c, to).
Inside the Pentagon, in turn, is a Heptagon drawn in such a way that its top side touches the center tip of the pentagram, and the pages of this heptagon should be labeled with the names of seven angels and archangels (Cafziel, Satquiel, Amael , Raphael, Anael, Michael, Gabriel).
From this first Heptagon is a second and a third drawing, whose description is hard to understand and has been interpreted differently in the manuscript illustrations, but has usually seven key points with crosses and labelled with two rows of God's: a first series of seven names of God, each in three syllables or components disassembled and relating spatially with those on the initial and final syllables of the last names of angels and vertices of the figure, namely la-ya- ly (to Cafziel), na-ra-th (to Satquiel), ly-bar-re (to Raphael), ly-ba-res (to Michael), (e) t-ly-alg (to Samael), ve -h-am (to Anael), and y-al-gal (to Gabriel); also in sub-segments seven more: Vos, Duynas, Gyram, Gram, Aysaram, Alpha and Omega, a third series El, On, El, On, Electric, On, Omega; as additions to the registered crosses the four letters a, g, a, l; and finally another group of five names of God Ely, Eloy, Christ, and Sother Adonay.
The color of the seal of the Liber iuratus indicates that the pentagram is usually red, purple with yellow faces, the first Heptagon blue, second yellow, the third yellow and the black circles, and also the area between the circles and all other surfaces were to turn green. In magical operations this would be handled differently - instead drawn on virgin parchment with blood of the mole, pigeon, hoopoe, bat or other animals, such as cattle, horses or deer.
Different versions of the Sigillum Dei are known from the tradition of the Clavicula Salomonis, specifically from an Italian manuscript in the collection of Heimann Joseph Michael in the Bodleian Library (MS. Michael 276); and John Aubrey in 1674 made a copy, also in the Bodleian Library (MS. Aubrey 24).
One of the oldest surviving manuscripts of the Liber iuratus, dating from the end of the 14th or the beginning of the 15th century, is manuscript No. 313 from the collection of Hans Sloane in the British Museum. It was partly owned by the mathematician and magical experimenter John Dee, in whose Mysteriorum libri Quinti, or Five books of mystical exercises (1581–1583), the Sigillum Dei played a central role and gained the suffixv Sigillum Dei: Emeth or Aemeth ("Truth") .
For John Dee, who received the authoritative description of the seal in 1582 via his medium and employee Edward Kelley, this scholarly and antiquarian interest was ultimately subordinate to the purpose of practical application. This can be contrasted with Athanasius Kircher, who devoted a detailed explanation to the Sigillum Dei in his Oedipus aegyptiacus , who linked the rejection of magical practice with a scholarly effort to understand the Christian, Jewish, Arab-Muslim and pagan parts and separate them.
- ↑ Gösta Hedegård: Liber iuratus Honorii: A Critical Edition of the Latin Version of Sworn Book of Honorius, Institutionen for Klassiska Språk, Stockholm 2002 (= Acta Universitatis Stockholmiensis, Studia Latina Stockholmiensia, 48); vgl. auch Jean Patrice Boudet: Magie théurgique, angéologie, et vision béatifique dans le Liber sacratus sive iuratus attribué à Honorius de Thèbes, in: Mélanges de l'École française de Rome: Moyen-Âge 114,2 (2002), S. 851-890, Text S. 871-890; nur mit Vorsicht zu gebrauchen sind die englischen Ausgaben von Daniel J. Driscoll, The Sworn Book of Honorius the Magician, Heptangle Press, Gillette (N.J.) 1977, 2. Ausg. 1983, und von Joseph H. Peterson auf http://www.esotericarchives.com/juratus/juratus.htm
- ↑ Robert Mathiesen, A Thirteenth Century Ritual to Attain the Beatific Vision from the Sworn Book of Honorius of Thebes, in: Claire Fangier (Hrsg.), Conjuring Spirits: Texts and Traditions of Ritual Magic, Sutton, Stroud 1998, S. 144ff., S. 146f.
- ↑ Jean Patrice Boudet,Magic théurgique ... (2002), p. 858f.
- ↑ Boudet, Magie théurgique... (2002), S. 876: "Primo fac unum circulum, cujus diameter sit trium digitorum propter tres clavos Domini, vel 5 propter quinque plagas, vel 7 propter 7 sacramenta, vel 9 propter 9 ordines angelorum, sed communiter 5 digitorum fieri solet. Deinde infra illum circulum, fac alium circulum a primo distantem duobus granis ordei propter duas tabulas Moysi vel distantem a primo tribus granis propter Trinitatem personarum."
- ↑ John Dee's Conversations with Angels: Cabala, Alchemy, and the End of Nature, Cambridge University Press, Cambridge etc. 1999, p. 35ff.
- ↑ Athanasius Kircher:Oedipi Aegyptiaci Tomi secundi Pars AlteraVitale Mascardo, Rome 1653, Class. IX (Magia Hieroglyphica), cap. VIII ram,. II, § IV (Amuleti alterius Cabalistici heptagoni interpretatio), p. 479-481, permanent/library/MQGPP987/pageimg ECHO online version, HTML rendering by Joseph H. Peterson