That City Is Mine!
In the ancient world, each city had a patron god or goddess. The people prayed to various deities, of course, but they usually held one in the highest regard. A temple was often built in that deity's name, and this temple was the town's primary place of worship. Worshipers also erected statues of the deity. Although individuals conducted their own sacrifices, public sacrifice to the patron god or goddess became a major civic event. Poseidon recognized the power afforded by this system and tried to gain the favor of as many cities as possible. This ambition sometimes brought him into conflict with other Olympians.
At Odds with Athena
Poseidon came into conflict with Athena over the city of Athens. Even before this happened, Poseidon bore several grudges against his niece. Poseidon was considered the least clever of the Olympian gods, and Athena was the goddess of wisdom. He was the god of the sea and wanted the ocean reserved for his creatures alone. When Athena taught mortals the art of shipbuilding, she opened up Poseidon's domain to humans. Remember, too, that some myths credit Poseidon with creating the horse, a wild and beautiful beast. Athena gave the bridle to mortals, enabling people to tame Poseidon's creation and use it for their own purposes. So a good deal of animosity already existed between the two deities — and this was heightened when each claimed the city of Athens.
Some myths say that Athens belonged to Poseidon first. In these myths, Poseidon struck his trident into the ground at the Acropolis and created a spring; however, since he was god of the sea, the spring was salty. Later, Athena came along and planted an olive tree, claiming the city as hers. Poseidon, hotheaded as always, challenged Athena to a fight. Zeus interceded but felt he couldn't judge the matter fairly, so he took the argument before others.
One myth states that Zeus allowed the people of Athens to choose their deity by deciding which of the two gifts was more useful. The people judged that the olive tree was more useful than a saltwater spring, so Athena became protector of the city.
Another myth says that Zeus put the dispute before the other Olympians. The gods voted for Poseidon, and the goddesses voted for Athena. Zeus abstained, leaving Poseidon one vote shy of a tie, and Athena claimed the city.
Yet another myth says that Zeus took the matter to Cecrops and Cranaus, early kings of Attica. Cecrops was biased toward Athena and maintained that her claim to the city preceded Poseidon's. Therefore, the arbitrators ruled in Athena's favor.
The myths agree that Athena won the city, and this is where the name Athens came from. In retaliation, Poseidon sent water to flood the Attic Plain, the countryside around the city. Eventually, Zeus intervened and reconciled his brother and the people of Athens, who honored Poseidon as second only to Athena.
Never Give Up
Poseidon didn't give up easily. He continued to challenge the gods and goddesses for the patronage of other cities. Numerous disputes took place, and more often than not Poseidon was the loser. Here are some of the better-known conflicts:
He challenged Dionysus for the island of Naxos and lost.
He wanted Delphi but had to go up against Apollo, who won.
He competed again with Athena for Troezen, and lost.
He challenged Zeus for Aegina. Zeus, of course, won.
He challenged Hera for the city of Argos, but the Queen of the Heavens won.
When Poseidon challenged Hera for Argos, Zeus appointed Phoroneus to act as judge. Phoroneus, who was credited with dividing people into cities in the first place, awarded the city to Hera. Instead of flooding the area as he had done when he lost Athens to Athena, Poseidon dried up the region's water sources.
Despite these setbacks, many cities honored Poseidon as their chief god — including Corinth, Helike, and Aegae — and representatives of the twelve cities of the Ionian League met every year at a temple of Poseidon.