Portunus
or PORTUMNUS, the protecting genius of harbours among the Romans. He was invoked to grant a happy return from a voyage. Hence a temple was erected to him at the port of the Tiber, from whence the road descended to the port of Ostia. At his temple an annual festival, the Portunalia, was celebrated on the 17th of August. (Varro, De Ling. Lat. 6.19; Arnob. 3.23; Cic. de Nat. Deor. 2.26; Verg. A. 5.241.) He was represented with a key in his hand, portus as well as porta signifying a place which can be closed. At the time when the Romans became familiar with Greek mythology, Portunus was identified with the Greek Palaemon (Festus, s. v. Portunus, p. 242, ed. Muller; comp. PALARMON.)
From William Smith (ed.), Dictionary of Greek and Roman Biography and Mythology. 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.