Starting from a famous passage by Ovid (Fasti II.127-132), in which the poet repre- sents Augustus as “sanctus pater patriae”, as well as “pater orbis” and “pater hominum”, the article examines the title of pater patriae (conferred to Augustus, by Valerio Massala, on behalf of the Senate, in 2 AD). This appellation (already used for Romulus, Gaius Marius and Cicero) seems to recall, and at the same time to differ from, that of parens patriae (attributed, in addition to the conditor itself, to Furius Camillus and Caesar). The two names seem to reflect, at a civic and communitarian level, the two different forms of paternity in the Roman world: that of the parens, the biological father, and that of the pater familias, the oldest living progenitor, priest of the sacra familiaria and sole holder of patria potestas, to which concepts of auctoritas and sanctitas are related. The princeps “pater patriae” therefore seems to extend his “augusta potestas” all over the men of the patria, which coincides with the orbis, the whole world.