The son of Picus and father of Latinus, was the third in the series of the kings of the Laurentes. In his reign Faunus, like his two predecessors, Picus and Saturn, had promoted agriculture and the breeding of cattle among his subjects, and also distinguished himself as a hunter. (Plin. H. N. ix. 6; Propert. iv. 2. 34.) In his reign likewise the Arcadian Evander and Hercules were believed to have arrived in Latium. (Plut. Parall. Gr. et Rom. 38.) Faunus acts a very prominent part in the mythical history of Latium, for, independent of what he did for agriculture, he was regarded as one of the great founders of the religion of the country; hence Lactantius (i. 24, § 9) places him on an equality with Numa.
He was therefore in later times worshipped in two distinct capacities: first, as the god of fields and shepherds, and secondly, as an oracular and prophetic divinity. The festival of the Faunalia, which was celebrated on the 5th of December, by the country people, with great feasting and merriment, had reference to him as the god of agriculture and cattle. (Horat. Carm. iii. 18.) As a prophetic god, he was believed to reveal the future to man, partly in dreams, and partly by voices of unknown origin. (Virg. Aen. vii. 81, &c.; Cic. de Nut. Deor. ii. 2, iii. 6, de Divin. i. 45.) What he was in this respect to the male sex, his wife Fauna or Faula was to the female, whence they bore the surnames Fatuus, Fatua, or Fatuellus, Fatuella, derived from fari, fatum. (Justin, xliii. 1; Lactant. i. 22.) They are said to have given their oracles in Saturnian verse, whence we may perhaps infer that there existed in Latium collections of oracles in this metre. (Varro, de L. L. vii. 36.) The places where such oracles were given were sacred groves, one near Tibur, around the well Albunea, and another on the Aventine, near Rome. (Virg. l. c.; Ov. Fast. iv. 649, &c.) The rites observed in the former place are minutely described by Virgil : a priest offered up a sheep and other sacrifices; and the person who consulted the oracle had to sleep one night on the skin of the victim, during which the god gave an answer to his questions either in a dream or in supernatural voices. Similar rites are described by Ovid as having taken place on the Aventine. (Comp. Isidor. viii. 11, 87.) There is a tradition that Numa, by a stratagem, compelled Picus and his son Faunus to reveal to him the secret of calling down lightning from heaven [ELICIUS],and of purifying things struck by lightning. (Arnob. v. 1; Plut. Num. 15; Ov. Fast. iii. 291, &c.)
At Rome there was a round temple of Faunus, surrounded with columns, on Mount Caelius and another was built to him, in B. C. 196, on the island in the Tiber, where sacrifices were offered to him on the ides of February, the day on which the Fabii had perished on the Cremera. (Liv. xxxiii. 42, xxxiv. 53; P. Vict. Reg. Urb. 2; Vitruv. iii. 1; Ov. Fast. ii. 193.)
In consequence of the manner in which be gave his oracles, he was looked upon as the author of spectral appearances and terrifying sounds (Dionys. v. 16); and he is therefore described as a wanton and voluptuous god, dwelling in woods, and fond of nymphs. (Horat. l. c.) The way in which the god manifested himself seems to have given rise to the idea of a plurality of fauns (Fauni), who are described as monsters, half goat, and with horns. (Ov. Fast. v. 99, Heroid. iv. 49.) Faunus thus gradually came to be identified with the Arcadian Pan, and the Fauni as identical with the Greek Satyrs, whence Ovid (Met. vi. 392) uses the expression Fauni et Satyri fratres. As Faunus, and afterwards the Fauni, were believed to be particularly fond of frightening persons in various ways, it is not an improbable conjecture that Faunus may be a euphemistic name, and connected with faveo. (Hartung, Die Relig. d. Röm. vol. ii. p. 183, &c.)