NEPTUNE, GOD (Lat. NEPTUNUS), an Italian god, of unknown origin and meaning, paired with Salacia, possibly the goddess of the salt water. At an early date (399 B.C.) he was identified with the Greek Poseidon (?..), when the Sibylline books ordered a lectisternium in his honour (Livy v. 13). His festival, Neptunalia, at which tents were made from the branches of trees, was celebrated on the 23rd of July, and his temple, containing a famous marine group by Scopas, stood near the Circus Flaminius. In earlier times it was the god Fortunus who was thanked for naval victories; but Sextus Pompeius called himself son of Neptune, and Agrippa dedicated to Neptune a temple (Basilica Neptuni) in the Campus Martius in honour of the naval victory of Actium.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)