Poseidon was the god of the sea, earthquakes, floods, drought and horses. He was depicted as a mature man with a sturdy build and dark beard holding a trident.
Residence: Mount Olympus or the Sea
Symbols: Trident, fish, dolphin, horse and bull
Parents: Cronus and Rhea
Siblings: Hestia, Hades, Hera, Demeter, Zeus and Chiron
Consort: Amphitrite, Aphrodite and Demeter
Children: Theseus, Triton, Polyphemus, Orion, Belus, Agenor and Neleus
Roman equivalent: Neptune
After the Titanomachy, Poseidon and his brothers drew lots for the division of the world and won the Sea as his domain.
Both Athena and Poseidon wanted to be the patron of Athens. They agreed that each would give the Athenians one gift and the Athenians would choose whichever gift they preferred. Poseidon struck the ground with his trident and a spring sprang up; the water was salty and not very useful, whereas Athena offered them an olive tree. The Athenians or their king, Cecrops, accepted the olive tree and along with it Athena as their patron, for the olive tree brought wood, oil and food. After the fight, infuriated at his loss, Poseidon sent a monstrous flood to the Attic Plain, to punish the Athenians for not choosing him.
Walls of Troy
Poseidon and Apollo, having offended Zeus by their rebellion in Hera‘s scheme, were temporarily stripped of their divine authority and sent to serve King Laomedon of Troy. He had them build huge walls around the city and promised to reward them well, a promise he then refused to fulfill. In vengeance, Poseidon sent a sea monster to attack Troy. The monster was later killed by Heracles.