Notice the old and odd spelling of the name Poseidon along the left.

Poseidon is familiar from various myths. After the gods defeated the Titans in the Titanomachy, Poseidon and his two brothers, Zeus and Hades, split the realms. Poseidon's lot was the sea. Poseidon and his niece Athena competed for sponsorship of Athens. As the name of the polis indicates, Athena won. Ovid tells the story of how Poseidon desecrated Athena's temple by seducing Medusa, who was at the time very beautiful, there.

Athena punished Medusa with her snaky locks that turned men to stone. Perseus decapitated her. Another time, Poseidon sent a sea monster (Cetus) to ravage the princess Andromeda as punishment for a boast made by her mother, the queen of Ethiopia. Perseus rescued Andromeda before the monster arrived. Poseidon was also thwarted in his attempt to punish Odysseus, but at least there, Odysseus had ten years of suffering at the sea god's hand.