What is "flamen dialis"

Flamen \Fla"men\, n.; pl. E. Flammens, L. Flamines. [L.] (Rom. Antiq.) A priest devoted to the service of a particular god, from whom he received a distinguishing epithet. The most honored were those of Jupiter, Mars, and Quirinus, called respectively Flamen Dialis, Flamen Martialis, and Flamen Quirinalis.

Affrights the flamens at their service quaint.
--Milton.

In ancient Roman religion, the Flamen Dialis was the high priest of Jupiter. There were 15 flamines, of which three were flamines maiores, serving the three gods of the Archaic Triad. According to tradition the flamines were forbidden to touch metal, ride a horse, or see a corpse.

The office of Flamen Dialis, and the offices of the other flamines maiores, were traditionally said to have been created by Numa Pompilius, second king of Rome, although Numa himself performed many of the rites of the Flamen Dialis.