The Greek equivalent of the Roman God Neptune was Poseidon. He was the God of the sea, earthquakes, and horses. Like Neptune, Poseidon was depicted holding a trident, which represented his power over the sea. He was one of the twelve Olympian gods and was considered one of the most powerful. Poseidon was also known for his temperamental nature and was often involved in disputes with other gods and mortals alike. His worship was widespread throughout the Greek world, and many ancient cities had temples dedicated to him.