Who was poiesiden?

Poseidon is a prominent deity in ancient Greek mythology, known as the god of the sea, earthquakes, and horses. He was one of the twelve Olympian gods, often depicted wielding a trident and associated with both the calming and destructive forces of the ocean. Poseidon was the brother of Zeus and Hades, and his Roman counterpart is Neptune. He played a significant role in various myths, including the contest for the city of Athens against Athena.