Quintus Caecilius Metellus Pius
"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.