King Neptune is the ancient Roman God of the Sea whereas Poseidon is the Greek God of the Sea. While they are similarly depicted, many believe the Romans adopted Poseidon and changed his name to Neptune, therefore most believe them to be the same God with different names. Neptune was the brother of the God Pluto, god of the underworld (Hades) and King of the Gods, Jupiter (Zeus). Neptune was known for his violent temper, vindictiveness and unpredictable nature; reflective of the nature of the sea. He was also considered to be responsible for earthquakes when he became angry.
Usually seen with his three pronged trident, he would be the god given credit for the Roman’s victories at sea. He is also noted to be the father of Pegasus and Atlas in Greek mythology as Poseidon. Metropolitan Galleries offers a few different variations of Neptune and Poseidon listed below.