On 11 July 2011, Neptune completed its first full orbit since its discovery in 1846. Neptune was discovered by Jean Joseph Le Verrier. The planet was not known to ancient civilizations because it is not visible to the naked eye. The planet was initially called Le Verrier after its discoverer.
Neptune, Latin Neptunus, in Roman religion, originally the god of fresh water; by 399 bce he was identified with the Greek Poseidon and thus became a deity of the sea. His female counterpart, Salacia, was perhaps originally a goddess of leaping springwater, subsequently equated with the Greek Amphitrite.