Poseidon, the God of all water sources, earthquakes, floods, and droughts is Zeus’ and Hades’ brother. His mother is called Rhea and she is/was the queen of the Titans. When he was young, he was eaten by his father, Cronos, king of the Titans but luckily his younger brother, Zeus saved him, Hades, Hestia, Hera and Dementer.
Back in ancient Greece, in Athens, Poseidon and Athena competed to be the patron God of the city. To impress the Athenians, Poseidon created the first spring ( Not the season) that was bubbling with hot water. His opponent, Athena, created the first olive tree which is now one of her symbols along with the snake and the owl. In the end, Athena bested Poseidon and became the patron of Athens.
One of Poseidon’s symbols is a horse because he created the first one. Because of this all types of horses like him, such as, regular horses, unicorns, pegasi and. Another symbol of Poseiden is the Trident which played a big role in defeating Kronos and was made by the elder cyclopses along with the Dark Helm for Hades and the Master Bolt for Zeus.
When Zeus and Poseidon had arguments in Olympus, all the other Gods were scared because it was like the sea fighting the sky. To try and solve this, Rhea ( Mother of the big three and Hestia, Hera and Dementer) suggested that Poseiden should move underwater and build his own Palace and learn from the Telkhines ( A cross between a dog and a seal). He did this and built his Palace (Which was called Atlantis) and learned how to use his Trident properly.