Portunus (mythology)

[2] Portunus' festival, celebrated on August 17, the sixteenth day before the Kalends of September, was the Portunalia, a minor occasion in the Roman year.

Portunus appears to be closely related to the god Janus, with whom he shares many characters, functions and the symbol of the key.

The relationship between the two gods is underlined by the fact that the date chosen for the dedication of the rebuilt temple of Janus in the Forum Holitorium by emperor Tiberius is the day of the Portunalia, August 17.

[5] Linguist Giuliano Bonfante has speculated, on the grounds of his cult and of the meaning of his name, that Portunus should be a very archaic deity and might date back to an era when Latins lived in dwellings built on pilings.

[6] He argues that in Latin the words porta (door, gate) and portus (harbour, port) share their etymology from the same Indo-European root meaning ford, wading point.