Portunalia
Portunalia (a more correct spelling than Portumnalia), a festival celebrated in honour of Portunus on the 17th of August. It is called also Tiberinalia (Fast. Philocal.), and Mommsen thence deduces that Portunus=Tiberinus (C. I. L. i. p. 399); but Marquardt is probably right in taking Portunus not to be the River God, but the protecting deity of the wharves on the Tiber at Rome and of those at Ostia. He was deus portuum
(Cic. de Nat. Deor. 2.2. 6, 66; cf. Verg. A. 5.241). The festival was celebrated in two places: at Rome by the Pons Aemilius (Cal. Amit.), and at Ostia (Varro, L. L. 6.19). The connexion of Portunus with Tiberinus, the son of Janus, and therefore of his worship with that of Janus, may explain his being also termed deus portarum
(Fest. Ep. p. 56, 6).
From William Smith (ed.), Dictionary of Greek and Roman Antiquities. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.