Pontifex, the title borne by the members of one of the two great colleges among the ancient Romans, instituted for the purpose of preserving and cultivating religious knowledge; the other was the college of Augurs. The name seems obviously to be derived from pons, 'bridge,' and the root of ficio, 'I make;' but in what way the pontifices were connected with bridge-making is obscure. It is natural to suggest that it was in some way through the sacred bridge across the Tiber, the pons sublimus. It is customary to speak of the college of pontiffs as a 'priesthood;' it was not, however, strictly speaking, such—that is to say, the members were not charged with the worship of any particular divinity, nor did they conduct sacrifices. Their duties embraced the regulation of all the religious rites and ceremonies of a state—how the gods should be worshipped, how burials should be conducted, how the manes of the dead should be appeased. To them was entrusted the care of the calendar, the proclamation of festival days, &c. They also saw that every religious and every judicial act took place on the right day. 'As they had thus,' says Mommsen, 'an especial supervision of all religious observances, it was to them in case of need (as on occasion of marriage, testament, or arrogatio) that the preliminary question was addressed, whether the matter proposed did not, in any respect, offend against divine law.' In matters of religion they were the supreme authorities; from their decisions there was no appeal, and they themselves were responsible neither to the senate nor the people; further, they had power to inflict punishment on such priests as dared to disobey their injunctions and deviate into schismatical courses. The words of Festus are: rerum quæ ad sacra et religiones pertinent, JUDICES ET VINDICES. Their president was termed pontifex maximus.
The pontiffs, according to Roman tradition, were instituted by Numa, but as they appear in all the Latin communities they are regarded by Mommsen as a thoroughly national Italian institution, and probably found a place in the earliest religious organisation of the Latin race. Their number was originally four, or, including the pontifex maximus, five, all of whom were taken from the patricians. In 300 B.C. the Ogulnian Law raised the number to nine, four of whom were to be plebeians. The first plebeian, however, who attained the dignity of pontifex maximus was Tib. Coruncanius, 254 B.C. Sulla, in 81 B.C., again increased the number to fifteen, and Julius Cæsar to sixteen. During the empire the functions of pontifex maximus were generally discharged by the emperors themselves; and the name survived even the establishment of Christianity, occurring in inscriptions of Valentinian, Valens, and Gratianus; but at length the emperors dropped it, when it was assumed by the Christian bishops of Rome, and now this title forms one of the designations of the pope.