College of Pontiffs in the context of "Pontifices"

The pontifex maximus (Latin for 'supreme pontiff') was the chief high priest of the College of Pontiffs (Collegium Pontificum) in ancient Rome. This was the most important position in the ancient Roman religion, open only to patricians until 254 BC, when a plebeian first held this position. Although in fact the most powerful office in the Roman priesthood, the pontifex maximus was officially ranked fifth in the ranking of the highest Roman priests (Ordo Sacerdotum), behind the Rex Sacrorum and the flamines maiores (Flamen Dialis, Flamen Martialis, Flamen Quirinalis).

A distinctly religious office under the early Roman Republic, it gradually became politicized until, beginning with Augustus, it was subsumed into the position of emperor in the Roman imperial period. Subsequent emperors were styled pontifex maximus well into Late Antiquity, including Gratian (r. 367–383), but during Gratian's reign the phrase was replaced in imperial titulature with the Latin phrase: pontifex inclytus ("honourable pontiff"), an example followed by Gratian's junior co-emperor Theodosius the Great and which was used by emperors thereafter including the co-augusti Valentinian III (r. 425–455), Marcian (r. 450–457) and the augustus Anastasius Dicorus (r. 491–518). The first to adopt the inclytus alternative to maximus may have been the rebel augustus Magnus Maximus (r. 383–388).

The Roman calendar was the calendar used by the Roman Kingdom and Roman Republic. Although the term is primarily used for Rome's pre-Julian calendars, it is often used inclusively of the Julian calendar established by Julius Caesar in 46 BC.

According to most Roman accounts, their original calendar was established by their legendary first king Romulus. It consisted of ten months, beginning in spring with March and leaving winter as an unassigned span of days before the next year. These months each had 30 or 31 days and ran for 38 nundinal cycles, each forming a kind of eight-day week—nine days counted inclusively in the Roman manner—and ending with religious rituals and a public market. This fixed calendar bore traces of its origin as an observational lunar one. In particular, the most important days of each month—its kalends, nones, and ides—seem to have derived from the new moon, the first-quarter moon, and the full moon respectively. To a late date, the College of Pontiffs formally proclaimed each of these days on the Capitoline Hill and Roman dating counted down inclusively towards the next such day in any month. (For example, the year-end festival of Terminalia on 23 February was called VII. Kal. Mart., the 6th day before the March kalends.)

In Roman antiquity, a pontiff (from Latin pontifex) was a member of the most illustrious of the colleges of priests of the Roman religion, the College of Pontiffs. The term pontiff was later applied to any high or chief priest and, in Roman Catholic ecclesiastical usage, to bishops, especially the pope, who is sometimes referred to as the Roman pontiff or the supreme pontiff.

A flamen (plural, flamines) was a specific type of priest ("sacerdos") in the ancient Roman religion and one of the oldest classes of the Roman priesthood, with origins likely predating the Republican era. These flamines, of which there were fifteen, were high-ranking members of the College of Pontiffs who administered and oversaw the various cults of the state-sponsored religion, both collectively and individually. The most important of these were the three flamines maiores ("major priests"), who each served one of the gods of the Archaic Triad: Jupiter, Mars, and Quirinus. The remaining twelve flamines minores ("lesser priests") served various minor deities, of whom little is definitively known, with two of their identities even being forgotten. While these original flamines lost most of their cultural and religious significance by the dawn of the Empire, the term flamen went on to be used in reference to priests of the cults of deified Emperors (divus).