Titus Livius (Livy), The History of Rome, Book 1
D. Spillan, A.M., M.D., Ed.

20. Next he turned his attention to the appointment of priests, though he performed many sacred rites himself, especially those which now belong to the flamen of Jupiter. [2] But, as he imagined that in a warlike nation there would be more kings resembling Romulus than Numa, and that they would go to war in person, he appointed a residentiary priest as flamen to Jupiter, that the sacred functions of the royal office might not be neglected, and he distinguished him by a fine robe, and a royal curule chair. To him he added two other famines, one for Mars, another for Quirinus. [3] He also selected virgins for Vesta, a priesthood derived from Alba, and not foreign to the family of the founder. That they might be constant attendants in the temple, he appointed them salaries out of the public treasury; and by enjoining virginity, and other religious observances, he made them sacred and venerable. [4] He selected twelve Salii for Mars Gradivus, and gave them the distinction of an embroidered tunic, and over the tunic a brazen covering for the breast. He commanded them to carry the celestial shields called ¹Ancilia, and to go through the city singing songs, with leaping and solemn dancing. [5] Then he chose out of the number of the fathers Numa Marcius, son of Marcus, as pontiff,² and consigned to him an entire system of religious rites written out and sealed, (showing) with what victims, upon what days, and in what temples the sacred rites were to be performed; and from what funds the money was to be taken for these expenses. [6] He placed all religious institutions, public and private, under the cognisance of the pontiff, to the end that there might be some place where the people should come to consult, lest any confusion in the divine worship might be occasioned by neglecting the ceremonies of their own country, and introducing foreign ones. [7] (He ordained) that the same pontiff should instruct the people not only in the celestial ceremonies, but also in (the manner of performing) funeral solemnities, and of appeasing the manes of the dead; and what prodigies sent by lightning or any other phenomenon were to be attended to and expiated. [p. 29]To elicit such knowledge from the divine mind, he dedicated an altar on the Aventine to Jupiter ³Elicius, and consulted the god by auguries as to what (prodigies) should be expiated.