ARVALI, *FRATELLI*. — A collegial religious brotherhood of Roman type, composed of twelve members, headed by a *magister*; recruited from patrician families, with members co-opted until the imperial period, after which the emperors reserved the right to appoint them (*cooptatio ex litteris*). It was dedicated to the cult of the goddess Dia, a special aspect of the Mother or Celeris goddess, and possessed a sanctuary at the fifth milestone of the Via Campana (near present-day Magliana).
The great annual festival of the goddess lasted three days and fell at the end of May. It was directed toward propitiating the gods, especially the Lares, the Semones, Mars, and the goddess Dia on behalf of agriculture. The liturgical activity of this brotherhood is fairly well known thanks to the *Acts*, or minutes, unfortunately fragmentary, of their meetings, inscribed on stone and preserved in large numbers; the most notable for their extent are those from the years 218 and 240.
The festivals at the end of May were announced year by year and began in the *magister’s* house with libations, anointing, and other propitiatory rites. On the second day, which was the most solemn, the *fratres Arvales* went to the sanctuary on the Via Campana and there, after preliminary lustral ceremonies: 1) they sacrificed a fat lamb to the goddess Dia; 2) they offered to the Mother of the Lares handfuls of spelt, scattering them down the slope leading to the sanctuary; 3) they performed a *tripudium* in the temple, with doors closed, wearing tucked-up garments and reading from special booklets the most famous hymn: *Enos Lases invate*. This was followed by a banquet and races in the nearby hippodrome. The third day was spent in the *magister’s* house with a banquet, the lighting of lamps, and garlands of flowers.
The antiquity of this brotherhood is attested by the fact that Romulus himself was considered its founder; that the deities worshipped were all indigenous; that the language of the hymn is archaic, as were the ceremonies of its recitation; that it observed the *tabu* on iron and the continued use of crude oil, which recall those of the terramare culture; and that it performed archaic libations both in quality (offerings of dough kneaded with flour, milk, and liver) and in the manner of the oblation. Its *Acts* are therefore documents of primary importance for the study of the most ancient Roman liturgy. In the rite, the *fratres Arvales* wore the *praetexta* and had white *infulae* on their heads, upon which rested a crown of ears of grain. Their college lasted until the final years of paganism.