**Neptune** was the god of freshwater and the sea in ancient Roman religion. He is the counterpart of the Greek god **Poseidon**. Like Poseidon, Neptune was worshipped by the Romans also as a god of horses, under the name *Neptunus Equester*, a patron of horse-racing.
Neptune is one of the only three Roman gods to whom it was appropriate to sacrifice bulls, the other two being **Apollo** and **Mars**.