Precedence among Roman priests belonged to the rex sacrorum (“king of the sacred rites”), who, after the expulsion of the kings, took over the residue of their religious powers and duties that had not been assumed by the Republican officers of state. Nevertheless, the hold exercised by the rex sacrorum and his colleagues was weakened by the Law of the Twelve Tables (c. 451–450 bce), which displayed the secular arm exercising some control over sacral law. As late as c. 275 bce the religious calendar was still dated by the rex sacrorum but by this time he was already fading into the background.

Very early origins can also be attributed to some of the flamines, the priests of certain specific cults, and particularly to the three major flamines of Jupiter, Mars, and Quirinus. Jupiter’s priest, the flamen dialis, was encompassed by an extraordinary series of taboos, some dating to the Bronze Age, which made it difficult to fill the office in historic times.

Except for the rex sacrorum and flamen dialis, whose duties were unusually professional and technical, almost all Roman priesthoods were held by men prominent in public life. The social distinction and political prestige carried by these part-time posts caused them to be keenly fought for.

There were four chief colleges, or boards, of priests: the pontifices, augures, quindecimviri sacris faciundis, and epulones. Originally three, and finally 16 in number, the pontifices (whose name may recall antique tasks and magic rites in connection with bridges) had assumed control of the religious system by the 3rd century bce. The chief priest, the pontifex maximus (the head of the state clergy), was an elected official and not chosen from the existing pontifices. The augures, whose name may have been derived from the practice of magic in fertility rites and perhaps meant “increasers,” had the task of discovering whether or not the gods approved of an action. This they performed mainly by interpreting divine signs in the movements of birds (auspicia). Such divination was elevated, perhaps under Etruscan influence, into an indispensable preliminary to state acts, though the responsibility for the decision rested not with the priests but with the presiding state officials, who were said to “possess the auspices.” In private life too, even as late as Cicero and Horace in the 1st century bce, important courses of action were often preceded by consultation of the heavens. The Etruscan method of divining from the liver and entrails of animals (haruspicina) became popular in the Second Punic War, though its practitioners (who numbered 60 under the empire) never attained an official priesthood.

Of the other two major colleges, the quindecimviri (“Board of Fifteen,” who earlier had been 10 in number) sacris faciundis looked after foreign rites, and the members of the other body, the epulones, supervised religious feasts. There were also fetiales, priestly officials who were concerned with various aspects of international relationships, such as treaties and declarations of war. Also six Vestal Virgins, chosen as young girls from the old patrician families, tended the shrine and fire of Vesta and lived in the House of Vestals nearby, amid a formidable array of prehistoric taboos.

Shrines and temples

The Roman calendar, as introduced or modified in the period of the Etruscan kings, contained 58 regular festivals. These included 45 Feriae Publicae, celebrated on the same fixed day every year, as well as the Ides of each month, which were sacred to Jupiter, and the Kalends of March, which belonged to Mars. Famous examples of Feriae Publicae were the Lupercalia (February 15) and Saturnalia (December 17, later extended). There were also the Feriae Conceptivae, the dates of which were fixed each year by the proper authority, and which included the Feriae Latinae (“Latin Festival”) celebrated in the Alban Hills, usually at the end of April.

Templum is a term derived from Etruscan divination. First of all, it meant an area of the sky defined by the priest for his collection and interpretation of the omens. Later, by a projection of this area onto the earth, it came to signify a piece of ground set aside and consecrated to the gods. At first such areas did not contain sacred buildings, but there often were altars on such sites, and later shrines. In Rome, temples have been identified from c. 575 bce onward, including not only the round shrine of Vesta but also a group in a sacred area (S. Omobono), close to the river Tiber beside the cattle market (Forum Boarium). The great Etruscan temples, made of wood with terra-cotta ornaments, were constructed later and culminated in the temple of the Capitoline Triad. Subsequently, more solid materials, such as tuff (tufa), travertine, marble, cement, and brick, gradually came into use. Temple archives, now vanished, play a large part in the historical tradition, and the anniversaries of the vows to build the temples and their dedication were scrupulously remembered and celebrated on numerous coins.

Sacrifice and burial rites

The characteristic offering of the Romans was a sacrifice accompanied by a prayer or vow. (The Triumph, associated with Jupiter, was regarded as a thanksgiving in discharge of a vow.) Animal sacrifices were regarded as more effective than anything else, the pig being the commonest victim, with sheep and ox added on important occasions. Considered best of all were the basic elements of life: heart, liver, and kidneys. Human sacrifice, on the whole, was extraneous to Roman custom, though its practice among the Etruscans may have contributed to the institution of gladiatorial funeral games in both Etruria and Rome, and it was resorted to in major crises, notably during the Second Punic War (216 bce). Earlier in the century, and perhaps once before, a member of the family of the Decii had given up his life by self-sacrifice (devotio) in a critical battle.

Although ancestors were meticulously revered, there was nothing resembling the comprehensive Etruscan attention to the dead. In spite of elaborate philosophizing by Cicero and Virgil about the possibility of some sort of survival of the soul (especially for the deserving), most Romans’ ideas of the afterlife, unless they believed in the promises of the mystery religions, were vague. Such ideas often amounted to a cautious hope or fear that the spirit in some sense lived on, and this was sometimes combined with an anxiety that the ghosts of the dead, especially the young dead who bore the living a grudge, might return and cause harm. Graves and tombs were inviolable, protected by supernatural powers and by taboos. In the earliest days of Rome both cremation and inhumation were practiced simultaneously, but by the 2nd century bce the former had prevailed. Some 300 years later, however, there was a massive reversion to inhumation, probably because of an inarticulate revival of the feeling that the future welfare of the soul depended on comfortable repose of the body—a feeling that, as sarcophagi show, was fully shared by the adherents of the mystery cults, though, on the rational level, it contradicted their assurance of an afterlife in some spiritual sphere. The designs on these tombs reflect the soul’s survival as a personal entity that has won its right to paradise.

Religious art

A vast gallery of architecture, sculpture, numismatics, painting, and mosaics illustrates Roman religion and helps to fill the gaps left by the fragmentary, though extensive, literary and epigraphic record. Starting with primitive statuettes and terra-cotta temple decorations, this array eventually included masterpieces such as the Apollo of Veii. Other works of art, more than 400 years later, include paintings illustrating Dionysiac mysteries at Boscoreale near Pompeii, and the reliefs of Augustus’ Ara Pacis at Rome; and with the Christian emblems of Constantinian sarcophagi and coinage a thousand years of ancient Roman religious art comes to an end.