Nimbus (from the Latin, cloud, hence glory) is the name given in sacred art to the disk or halo which encircles the head of the sacred personage who is represented. Its use is almost universal in those religions of which we possess any artistic remains — the Indian, the Egyptian, the Etruscan, the Greek, and the Roman. It appears on Hindiu monuments of the most remote antiquity. The Hindfi goddess Maya is surrounded by a semi- aureole of light, and from the top of her head-dress and the neighborhood of her temples issue groups of stronger rays. The coincidence of this decoration with the Christian cruciform nimbus may be accidental. It occurs likewise in Roman sculpture and painting. The emperor Trajan ap. pears with it on the arch of Constantine; in the paintings found at Herculaneum it adorns Circe as she appears to Ulysses; and there are many examples of it in the Virgil of the Vatican. Hence its origin is involved in some obscurity; but a consideration of its various changes of form leads to the conclusion that it was originally meant to indicate light issuing from the head. The importance attached to an appearance of that kind, in remote times, as an augury of good, appears in many classical legends. It is illustrated in the second book of the Eneid by the flame descending upon the head of the young Iulus, which Anchises, versed in Oriental symbolism, saw with joy, and which proved to be an augury of good, though the other bystanders were alarmed at it;
"Ecce levis summo de vertice visus Iuli Fundere lumen apex, tactuque innoxia molles Lambere flamma comas, et circum tempora pasci. Nos pavidi trepidare metu, crinemque fagrantem Excutere, et sauctos restinguere fontibus ignes."
In the Hebrew Scriptures we trace, in the absence of representations, the same symbolized idea in the light which shone upon the face of Moses at his return from Sinai (Ex 34:29-35), and in the light with which the Lord is clothed as with a garment (Ps 103:1, Vulg.; civ. 1, Auth. Vers.); and in the N.T. in the transfiguration of Christ (Lu 9:31), and in the "crowns" of the just, to which allusion is so often made (2Ti 4:8; 1Pe 5:4; Re 4:4). Nevertheless, the nimbus, strictly so called, is comparatively recent in Christian art. It was originally given in Christian art to sovereigns and allegoric personages generally as the symbol of power or distinction; but with this difference, that around the heads of saintly and orthodox kings or emperors it is luminous or gilded; round those of Gentile potentates it is colored red, green, or blue. About the middle of the 3d century it begins to appear, and earliest on these glasses, as the special attribute of Christ; later it was given to the heads of angels, to the evangelists, to the other apostles, and finally to the blessed Virgin and all saints, but not as their invariable attribute till the 7th century (see Buonarotti, Vasi Antichi). What must seem strange, however, is that the nimbus does not appear at all on the sarcophagi, the most ancient of Christian monuments. This, together with the fact that the nimbus did not come into constant use in the West until the 8th century, leads to the supposition that it was borrowed by the Christian Church from the classical customs referred to above. After the 6th century we find the nimbus very frequent in Christian symbolism, more particularly in the Eastern Church, where it was far more generally used, until the cultivation of sacred art by the Western. Church made it almost a necessary appendage of all representations of God or of the saints.
Its ordinary form is the circular or semicircular; a form indeed in which later symbolists discover an emblem of perfection and of eternity; but the nimbus of the Eternal Father is often in the form of a triangle, and that of the Trinity an emanation of light, the rays of which form the three arms of a. cross. This intention to mark the divinity by this symbol is oftentimes made the more clear by. inscribing, on three branches of the cross (the fourth branch being concealed by the head), or at the three angles of the triangle, the letters Ε᾿γώεἰμι ῾Ο ῎ΩΝ, this being the name which God gave himself when he spoke to Moses from the burning bush, Ε᾿γώεἰμι ῾Ο ῎ΩΝ: "I am that I AM." The nimbus of the Virgin is sometimes, a simple ring, and sometimes a crown or diadem; occasionally it is encircled by an ornamental border, on which twelve stars are sometimes represented. Her nimbus, as well as that of the Divine Persons, is commonly of gold; but that of the Virgin Mary is occasionally in colors, as blue, red, purple, or white. The nimbus of the saints is ordinarily the semicircle or lunula. Didron mentions the curious instance of a picture of the traitor Judas with a black nimbus! In later art the nimbus became lighter and more aerial, melting, as it were, into the picture; and in Raphael's saints it occasionally fades into the very faintest indication of a golden tinge around the head . In the Eastern Church the use of the nimbus appears to have much less precise meaning.
It seems to claim consideration not only on the ground of sanctity, but of eminence of other kinds. It is applied to saints, and to many persons who are not saints-to kings, statesmen, and warriors. It frequently signifies power, and it is withheldl from beings destitute of this title to admiration. Thus in a miniature of the 12th century, the beast with seven heads (Re 12:1-3) wears a nimbus on six of them, but the seventh, which is "as it were wounded to death," is without it: and even Satan has it in a miniature of the 10th century.
In connection with the nimbus may also be mentioned two analogous forms the Aureole and the Glory. The former is an illumination surrounding not the head only, but the entire figure. If the figure be upright, the aureole is commonly oval, when it is called the vesica piscis, and is supposed to contain an allusion to the ichthys. With a seated figure it becomes circular, and is occasionally divided by radiating bands, in the form' of a wheel; sometimes it takes a quatrefoil form. It is commonly of gold, but occasionally also is in colors. The glory is a combination of the nimbus and the aiureole, and is chiefly seen in Byzantine pictures, and those of the early South German school.
The Latin word nimbus appears to agree in signification with the Greek νιφάς, of which νίφω is the original root, and which is used to express snow, shower, and even sometimes hail; it also signifies the place in which they are formed, i.e. clouds. Isidore of Seville, in his Origines, describes the nimbus as a transverse bandeau of gold, sewed on the veil, and worn by women on their forehead. The glory is constantly adopted by artists, both in painting and sculpture, as a characteristic ornament; it either encircles the head alone or the entire figure. As an attribute, it serves to denote a holy person, in the same manner as the crosier or the scepter distinguishes a bishop or a king. The etymology of the word has been little regarded by artists, for the nimbus, which ought always to have the character of a cloud, a vapor, or flakes of snow, frequently assumes the form of a circular disk, sometimes opaque, sometimes luminous, and sometimes transparent. It has the shape of a triangle or a square; that of several jets of flame; of a star, with six, eight, twelve, or sometimes even a countless number of rays. There is scarcely, perhaps, a single instance in which the shape of the nimbus agrees entirely with the idea which that word seems intended to convey. See Didron, Christian Iconography, 1:22 sq.; Siegel, Christliche
Alterthumer, I, 436, 437; 3:301 sq.; Walcott, Sacred Archaeol. s.v.; Martigny, Dict. des Antiquites Chret. p. 435-437.