"And likewise games were held and golden paterae placed at the temple of Ceres by the plebeian aediles L. Aelius Paetus and C Fulvius Curvus with the money from fines that they had collected from those convicted of [illegally] using public pasture." - Livy 10.23.13.
With the founding of the Republic in 500 BC, Ceres picked up a new association as the goddess of the plebeian class. They comprised the bulk of Rome's common citizens, and existed in opposition to the Roman aristocratic class, the patricians (Spaeth 6). The archives of the decrees of the Roman Senate and of the Concilium Plebes were stored in her temple by the plebeian aediles (85). The office of the tribune of the plebs was protected by Ceres directly. Anyone who harmed a tribune could be killed with impunity (Dumezil 195), and his goods consecrated to Ceres. The tribunes derived several other important powers from their association with the goddess. Among these were the right to protect plebs from patrician magistrates, ius auxilii, and the right to impede the action of any patrician magistrate, ius intercessionis. These two rights, sponsored by the goddess, helped make the tribune one of the strongest offices in the entire Roman government. The plebeian aediles may owe their very name to Ceres, as it may be derived from aedes Cereris, the Latin for "Temple of Ceres" (Spaeth 86). Fines levied by them were frequently presented to the goddess as gifts. Such fines were described by the legal term in sacram iudicare (90). At the beginning of the Cerealia, plebeian families typically invited each other to special banquets (92).
Several reasons for why Ceres was made goddess of the plebs have been suggested. One of the more convincing notes that her ancient associations with agriculture and fertility would have made her a commonly worshiped deity among Latin farmers. Another suggests that the Aventine Triad was to have grain importations as its focus, an association that would be compatible with Ceres' older associations with grain (9).
The patricians imported the cult of Magna Mater, or Cybele, explicitly so that their social class would have a goddess that served some of the functions that Ceres did for the plebeians. As a result, there was sharp antagonism between the two cults, who became rivals separated only by the social classes they served. The cult was imported from Pessinus in Asia Minor in 204 BCE, and welcomed into the city by a vir optimus, or best man, selected from one of the most distinguished patrician families. The matrons that escorted the goddess on the road from Ostia to Rome were entirely drawn from the patrician class. After the completion of Magna Mater's temple on the Palatine in 191 BCE, games were established in her honor in which patricians received special privileges and patrician families held banquets (92). Magna Mater's games, the ludi Megalenses, directly preceded the Cerialia and were celebrated by the curule aediles, who were drawn largely from the patrician class. The Palatine itself was a district largely associated with the patricians, and the temple of Ceres, Liber, and Libera on the Aventine directly faced the temple of Magna Mater that stood there (94).
The same year the temple of Magna Mater was dedicated, a new festival dedicated to Ceres was established. This festival was called the ieinium Cereris, and may have represented a plebeian response to the new patrician goddess. The festival lasted nine days and was originally held every five years (96), though it was held every year beginning on October 4 by the time of Augustus. In it, women fasted and offered the first wheat harvest to Ceres (Nova Roma, 3).
