The indigenous Italic religion, which was the nucleus of the religion of ancient Rome, was essentially animistic. It depended on the belief that forces or spirits, called numina (sing., numen ), existed in natural objects and controlled human destiny.
In the beginning of the historical period, when Italy was dotted with small agricultural communities, the family and the household were the basic religious units. Everything vital to the continuance of human life had its numen and appropriate rite. For the perpetuity of the family, the Italian farmer made offerings to the genius of the family. For the safety of the household he worshiped Vesta, the guardian spirit of the hearth fire; the lares and penates, guardians of the house; and Janus, guardian of the door. To protect the boundaries of his property he honored Terminus. To insure an abundant harvest he held various festivals throughout the year. To placate the spirits of the dead he made offerings to the lemures, to the manes, and to the deities of the underworld. In performing these religious ceremonies the head of the family acted as the priest and was assisted by his sons and daughters.
When these families coalesced into tribes and then a state, the family cult and ritual formed the basis of the state cult and ritual. Vesta had a community hearth, the penates a community storeroom, Janus a holy door in the Forum. Rome, which was theoretically one family, was ruled by its king, who as such was head of the family and chief priest. The king was assisted in his duties by his "sons and daughters," the colleges of priests and priestesses. They elaborated and recorded the rituals necessary for the propitiation of the gods and regulated the state ceremonies and the ceremonial calendar. The official clergy included the pontifex maximus, the rex sacrorum [king of the sacred rites], the pontifices, the flamens (see flamen), and the vestal virgins.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.