Pietas, translated variously as "duty", "religiosity" or "religious behavior", "loyalty", "devotion", or "filial piety" (English "piety" derives from the Latin), was one of the chief virtues among the ancient Romans. It was the distinguishing virtue of the founding hero Aeneas, who is often given the adjectival epithet pius ("religious") throughout Virgil's epic Aeneid. The sacred nature of pietas was embodied by the divine personification Pietas, a goddess often pictured on Roman coins. The Greek equivalent is eusebeia (εὐσέβεια).
Cicero defined pietas as the virtue "which admonishes us to do our duty to our country or our parents or other blood relations." The man who possessed pietas "performed all his duties towards the deity and his fellow human beings fully and in every respect," as the 19th-century classical scholar Georg Wissowa described it.
Pietas erga parentes ("pietas toward one's parents") was one of the most important aspects of demonstrating virtue. Pius as a cognomen originated as way to mark a person as especially "pious" in this sense: announcing one's personal pietas through official nomenclature seems to have been an innovation of the late Republic, when Quintus Caecilius Metellus Pius claimed it for his efforts to have his father, Numidicus, recalled from exile. Pietas extended also toward "parents" in the sense of "ancestors," and was one of the basic principles of Roman tradition, as expressed by the care of the dead.
Pietas as a virtue resided within a person, in contrast to a virtue or gift such as Victoria, which was given by the gods. Pietas, however, allowed a person to recognize the divine source of benefits conferred.
The first recorded use of pietas in English occurs in Anselm Bayly’s The Alliance of Music, Poetry, and Oratory, published in 1789.
"Pietas" can also be arranged in this order from the most important to the least (but just as important): The gods, your city, your family, and lastly yourself. You should also take in mind that "pietas" includes knowing your place in this scale.
Pietas was represented on coin by cult objects, but also as a woman conducting a sacrifice by means of fire at an altar. In the imagery of sacrifice, libation was the fundamental act that came to symbolize pietas.
Pietas is first represented on Roman coins on denarii issued by Marcus Herennius in 108 or 107 BC. Pietas appears on the obverse as a divine personification, in bust form; the quality of pietas is represented by a son carrying his father on his back. Pietas is among the virtues that appear frequently on Imperial coins, including those issued under Hadrian.
One of the symbols of pietas was the stork, described by Petronius as pietaticultrix, "cultivator of pietas." The stork represented filial piety in particular, as the Romans believed that it demonstrated family loyalty by returning to the same nest every year, and that it took care of its parents in old age. As such, a stork appears next to Pietas on a coin issued by Metellus Pius (on whose cognomen see above).
Pietas was the divine presence in everyday life that cautioned humans not to intrude on the realm of the gods. Violations of pietas required a piaculum, expiatory rites.
A temple to Pietas was vowed (votum) by Manius Acilius Glabrio at the Battle of Thermopylae in 191 BC.
According to a miraculous legend (miraculum), a poor woman who was starving in prison was saved when her daughter gave her breast milk (compare Roman Charity). Caught in the act, the daughter was not punished, but recognized for her pietas. Mother and daughter were set free, and given public support for the rest of their lives. The site was regarded as sacred to the goddess Pietas (consecratus deae) because she had chosen to manifest her presence there. The story exemplified pietas erga parentes, the proper devotion one ought to show to one's parents.
Pietas was often depicted as goddess on the reverse of Roman Imperial coins, with women of the imperial family on the obverse, as an appropriate virtue to be attributed to them. Women of the Imperial family might be portrayed in art in the goddess's guise.