Portūnus
or
Portumnus. The Roman god of harbours, though originally of doors
and gates (
portae). Like
Ianus
(q.v.), the god of coming in and going out, he was represented with a key, and was perhaps
only a personification of one attribute of Ianus. He had a special
flamen
in Rome (
Portunalis), and at the harbour on the Tiber he had a temple, where a
festival, the Portunalia, was held in his honour every year on
August 17th. In later times he was identified with the Greek
Palaemon (q.v.).