Portunus appears to be closely related to the god Janus, with whom he shares many characters, functions and the symbol of the key. He too was represented as a two headed being, with each head facing opposite directions, on coins and as figurehead of ships. He was considered to be "deus portuum et portarumque praeses" 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. Read more
Roman mythology, Portunes (alternatively spelled Portumnes or Portunus) was a god of keys, doors and livestock. He protected the warehouses where grain was stored. His festival, celebrated on August 16, the seventeenth day before the Kalends of September, was the Portumnalia, a minor occasion in the Roman year. Read more