Rex sacrorum

In ancient Roman religion, the rex sacrorum ("king of the sacred", also sometimes rex sacrificulus, "[one who makes] offerings made by the king") was a senatorial priesthood reserved for patricians. Although in the historical era the pontifex maximus was the head of Roman state religion, Festus says that in the ranking of the highest Roman priests (ordo sacerdotum), the rex sacrorum was of highest prestige, followed by the flamines maiores (Flamen Dialis, Flamen Martialis, Flamen Quirinalis) and the pontifex maximus. The rex was based in the Regia.

During the Roman Republic, the rex sacrorum was chosen by the pontifex maximus from a list of patricians submitted by the College of Pontiffs. A further requirement was that he be born from parents married through the ritual of confarreatio, which was also the form of marriage he himself had to enter. His wife, the regina sacrorum, also performed religious duties specific to her role. Marriage was thus such a fundamental part of the priesthood that if the regina died, the rex had to resign.

The rex sacrorum wore a toga, the undecorated soft "shoeboot" (calceus), and carried a ceremonial axe; as a priest of archaic Roman religion, he sacrificed capite velato, with head covered. The rex held a sacrifice on the Kalends of each month. On the Nones, he announced the dates of festivals for the month. On March 24 and May 24, he held a sacrifice in the Comitium.

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