Rex Nemorensis

The rex Nemorensis (Latin, "king of Nemi" or "king of the Grove") was a priest of the goddess Diana at Aricia in Italy, by the shores of Lake Nemi, where she was known as Diana Nemorensis. The priesthood played a major role in the mythography of James George Frazer in The Golden Bough; his interpretation has exerted a lasting influence.

The tale of the rex Nemorensis appears in a number of ancient sources. Ovid gives a poetic account of the priesthood of Nemi in his Fasti, Book 3 (on the month of March), noting that the lake of Nemi was "sacred to antique religion", and that the priest who dwelt there "holds his reign by strong hands and fleet feet, and dies according to the example he set himself." The Latin name of the priesthood is given by Suetonius: "He [Caligula] caused the rex Nemorensis, who had held his priesthood for many years, to be supplanted by a stronger adversary." That same passage indicates that by the time of the early Principate, the custom of succession in the office by combat had become subject to outside control.

The Greek geographer Strabo also mentions the institution: "and in fact a barbaric, and Scythian, element predominates in the sacred usages, for the people set up as priest merely a run-away slave who has slain with his own hand the man previously consecrated to that office; accordingly the priest is always armed with a sword, looking around for the attacks, and ready to defend himself."

Pausanias gives an etiological myth on the founding of the shrine:

...
Wikipedia