Titus Livius (Livy), The History of Rome, Book 1
Benjamin Oliver Foster, Ph.D., Ed.

20. He then turned his attention to the¹ appointment of priests, although lie performed very many priestly duties himself, especially those which now belong to the Flamen Dialis. [2] But inasmuch as he thought that in a warlike nation there would be more kings like Romulus than like Numa, and that they would take the field in person, he did not wish the sacrificial duties of the kingly office to be neglected, and so appointed a flamen for Jupiter, as his perpetual priest, and provided him with a conspicuous dress and the royal curule chair. To him he added two other flamens, one for Mars, the other for Quirinus. [3] In like manner he designated virgins for Vesta's service —a priesthood, this, that derived from Alba and so was not unsuited to the founder's stock. That they might be perpetual priestesses of the temple, he assigned them a stipend from the public treasury, and by the rule of virginity and other observances invested them with awe and sanctity. [4] He likewise chose twelve Salii for Mars Gradivus, and granted them the distinction of wearing the embroidered tunic and over it a bronze breastplate, and of bearing the divine shields which men call ancilia,² while they proceeded through the City, chanting their hymns to the triple beat of their solemn dance. [5] He next chose as pontifex Numa Marcius, son of Marcus, one of the senators, and to him he intrusted written directions, full and accurate, for performing the rites of worship; with what victims, on what days, in what temple, sacrifices should be offered, and from what sources money was to be disbursed to pay their costs. [6] All other public and private sacrifices lie likewise made subject to the decrees of the pontifex, that there [p. 73]might be someone to whom the commons could³ come for advice, lest any confusion should arise in the religious law through the neglect of ancestral rites and the adoption of strange ones. [7] And not merely ceremonies relating to the gods above, but also proper funeral observances and the propitiation of the spirits of the dead were to be taught by the pontifex as well, and also what prodigies manifested by lightning or other visible sign were to be taken in hand and averted. With the purpose of eliciting this knowledge from the minds of the gods, Numa dedicated an altar on the Aventine to Jupiter Elicius, and consulted the god by augury, that he might learn what portents were to be regarded.