Poseidon was the god of the sea, earthquakes, and horses, one of the three sons of the Titans Cronus and Rhea who divided the cosmos after the Titanomachy. He received dominion over all the waters of the earth, and his moods were said to govern the safety of sailors, the prosperity of coastal cities, and the rising of new lands. The Romans identified him with their own god Neptune.
Poseidon is the most complex of the three brothers who divided the cosmos after the Titanomachy. The Homeric Iliad treats him as the god of the sea, the earth-shaker (Ennosigaios), and the great rival of Athena for the patronage of cities; the Attic tragedies and the Hellenistic poets add the erotic, the quarrelsome, and the grudging — the Poseidon who built the walls of Troy and was cheated of his pay, the Poseidon who pursued Demeter and became the father of the horse Arion. The standard scholarly treatment of the enmity between Poseidon and Athena is in Jane Ellen Harrison’s Prolegomena to the Study of Greek Religion (1903, still in print).
The Name and Origins of Poseidon
The name Poseidon is debated, but most scholars connect it to the Greek words posis (husband, lord) and da (earth), giving the meaning “husband of the earth” or “lord of the earth.” This etymology reflects his older role as an earth-shaker and fertility deity before he became primarily a sea god.
Poseidon was one of the six children of the Titans Cronus and Rhea, and was swallowed by his father at birth, only to be disgorged later when Zeus tricked Cronus into vomiting up his siblings. He fought alongside his brothers and sisters in the Titanomachy, and after the victory, the three brothers drew lots to divide the cosmos. Poseidon received the sea.
The Symbols of Poseidon
Poseidon was associated with several distinctive symbols:
- The Trident: Poseidon’s primary symbol was the trident, a three-pronged spear, originally a fisherman’s tool. It was forged for him by the Cyclopes during the Titanomachy, and it was said to be able to shatter rocks, raise islands from the sea, and stir up storms.
- The Horse: Poseidon was sometimes called the “tamer of horses,” and the horse was sacred to him. According to one myth, he created the first horse.
- The Bull: Poseidon was often associated with bulls, and he sometimes took the form of a bull himself, including the famous bull that carried off Europa.
- The Dolphin: The dolphin was a friendly sea creature sacred to Poseidon.
- The Pine Tree: The pine tree was sacred to Poseidon.
The Domains of Poseidon
As god of the sea, Poseidon was the sovereign of all the waters of the world. He controlled the winds, the waves, the storms, and the calm. He could raise new islands from the sea, shatter ships with his trident, or fill the sea with sea-monsters at will. He was also the god of earthquakes, which the Greeks explained as the rage of the “earth-shaker” (Ennosigaios). When Poseidon was angry, the earth trembled.
In addition to his marine and chthonic domains, Poseidon was the god of horses and horse-racing. The first horse was said to have been born from the earth when Poseidon struck the ground with his trident, in a contest with Athena for patronage of Athens.
The Major Myths of Poseidon
The Contest with Athena for Athens
The most famous of Poseidon’s myths is his contest with Athena for patronage of Athens. Both gods wished to be the patron of the city, and the citizens agreed to accept the god who gave them the more useful gift.
Poseidon struck the rock of the Acropolis with his trident, and a spring of salt water gushed forth, along with (in some versions) the first horse. Athena planted an olive tree, which the Athenians considered more valuable. The city was named for Athena, and Poseidon was furious. The Athenians, in honor of both, built temples to both gods on the Acropolis.
The dispute is commemorated in the western pediment of the Parthenon, which depicts the contest between the two gods, and in the surviving temple of Poseidon at Cape Sounion, a few miles from Athens.
The Pursuit of Medusa
In one of the more troubling myths, Poseidon raped the beautiful maiden Medusa in the temple of Athena. Athena, furious at the desecration, transformed Medusa into a monster with snakes for hair, whose gaze could turn onlookers to stone. The myth has been read in various ways, with modern critics often focusing on the way it blames Medusa for the violence of a god.
The Wandering Odysseus
In Homer’s Odyssey, Poseidon is the chief adversary of Odysseus, who had blinded Poseidon’s son, the Cyclops Polyphemus. Poseidon pursues Odysseus across the sea, raising storms and shipwrecks, and is finally pacified only by the intervention of Zeus.
The Founding of Atlantis
In the dialogues of Plato, Poseidon is said to have fallen in love with a mortal woman named Cleito, and to have fathered five sets of twin sons on an island in the Atlantic Ocean. The eldest, Atlas, became the first king of Atlantis. According to Plato, the island of Atlantis was eventually destroyed by a great earthquake and flood, sinking beneath the sea in a single day and night. The story of Atlantis, told in the Timaeus and the Critias, has been the source of countless legends and conjectures ever since.
The Contest for Corinth
In a similar myth, Poseidon and Helios disputed over the city of Corinth, which was then called Ephyra. The arbitrator was Briareus, who awarded the city to neither god but gave the isthmus of Corinth to Poseidon and the heights of Acrocorinth to Helios.
The Walls of Troy
In the Iliad, Poseidon, along with Apollo, was said to have built the walls of Troy for King Laomedon, but Laomedon refused to pay them. The gods were furious, and Poseidon, in particular, would side against the Trojans in the later war. He sent a sea-monster to ravage the land, the famous story of Andromeda’s rescue, and he was instrumental in helping the Greeks.
The Marriage of Poseidon and Amphitrite
Poseidon’s wife was the Nereid Amphitrite, a sea-goddess. According to myth, Poseidon first saw her dancing with her sisters on the island of Naxos and fell in love, but she fled from him. He sent a dolphin to find her and persuade her to marry him, which she eventually did. The dolphin was rewarded by being placed among the stars as the constellation Delphinus. Their son Triton was a merman who blew a conch shell to calm or raise the waves.
The Children of Poseidon
Poseidon fathered many children, both gods and mortals:
- Triton, the merman, son of Amphitrite
- Theseus in some versions, son of Aethra
- Polyphemus, the Cyclops, son of Thoosa
- Orion, the giant hunter
- Pegasus, in some versions, born from the blood of Medusa
- Chrysaor, the giant with golden sword, born from the blood of Medusa
- Sciron, the bandit king
- Procrustes, the robber who stretched or cut off the legs of travelers
In myth, Poseidon was particularly associated with the founding heroes of many Greek cities, including Corinth, Troezen, and various Ionian colonies.
The Worship of Poseidon
The worship of Poseidon was panhellenic, with major centers in:
- The Isthmus of Corinth, where the Isthmian Games were held in his honor every two years
- Cape Sounion, the southern tip of Attica, where the famous temple of Poseidon still stands
- The island of Tenos, with a major sanctuary
- Pylos, the city of Nestor
- The city of Mantinea in Arcadia
The Romans identified Poseidon with Neptune, a relatively minor Italian god of the sea who became a much more important figure under Greek influence. The month of July was sometimes associated with Neptune, and the festival of Neptunalia was celebrated on July 23.
The Legacy of Poseidon
Poseidon is the father of the hero in the Percy Jackson series, a recurring antagonist in the God of War games, and the central figure of the Atlantis mythos in the Assassin’s Creed franchise (notably Odyssey). He appears in the Clash of the Titans films and in Madeline Miller’s Circe. For the broader modern reception, see our guide to Greek mythology in modern culture.
A Note on Reading This Profile
A note on reading this profile. Poseidon’s role in Greek myth is unusually hard to summarise, because the god was worshipped in many different ways across the Greek world, and the local traditions don’t always agree. The Pylaia, the council of the Greeks, met at Posidonion in Calauria, and the Ionians of Ionia (in the central Greek world) treated Poseidon as the special patron of the Ionian migrations. The four great games at Isthmia, Nemea, Olympia, and Delphi honoured Poseidon in different ways. The page above focuses on the literary tradition, but the cult tradition is the older one.