In ancient Roman religion, the Arval Brethren (Latin: Fratres Arvales, "Brothers of the Fields") or Arval Brothers were a body of priests who offered annual sacrifices to the Lares and gods to guarantee good harvests.Inscriptions provide evidence of their oaths, rituals and sacrifices.
Roman legend held that the priestly college was originated by Romulus, who took the place of a dead son of his nurse Acca Laurentia, and formed the priesthood with the remaining eleven sons. They were also connected originally with the Sabine priesthood of Sodales Titii who were probably originally their counterpart among the Sabines.
The brethren dated back to the time of Romulus, first king of Rome, even though it can be inferred from the story of Acca Larentia they existed before the founding of the city, and persisted to the imperial period. Their task was the worship of Dea Dia, an old fertility goddess, possibly an aspect of Maia or Ceres. On the three days of her May festival, they offered sacrifices and chanted secretly inside the temple of the goddess at her lucus the Carmen Arvale. The magister (master) of the college selected the exact three days of the celebration by an unknown method. The celebration began in Rome on the first day, was transferred to a sacred grove outside the city wall on the second day and ended back in the city on the third day.
Arval Brethren formed a college of twelve priests, although archaeologists have found only up to nine names at a time in the inscriptions. They were appointed for life and did not lose their status even in exile. According to Pliny the Elder, their sign was a white band with the chaplet of sheaves of grain (Naturalis Historia 18.2).