Poseidon was the son of Kronos and Rhea, and the brother of Zeus.
He was god of the sea, more particularly of the Mediterranean, and, like the element over which he presided, was of a variable disposition, now violently agitated, and now calm and placid, for which reason he is sometimes represented by the poets as quiet and composed, and at others as disturbed and angry.
In the earliest ages of Greek mythology, he merely symbolized the watery element; but in later times, as navigation and intercourse with other nations engendered greater traffic by sea, Poseidon gained in importance, and came to be regarded as a distinct divinity, holding indisputable dominion over the sea, and over all sea-divinities, who acknowledged him as their sovereign ruler.
He possessed the power of causing at will, mighty and destructive tempests, in which the billows rise mountains high, the wind becomes a hurricane, land and sea being enveloped in thick mists, whilst destruction assails the unfortunate mariners exposed to their fury. On the other hand, his alone was the power of stilling the angry waves, of soothing the troubled waters, and granting safe voyages to mariners. For this reason, Poseidon was always invoked and propitiated by a libation before a voyage was undertaken, and sacrifices and thanksgivings were gratefully offered to him after a safe and prosperous journey by sea.
The symbol of his power was the fisherman's fork or trident, by means of which he produced earthquakes, raised up islands from the bottom of the sea, and caused wells to spring forth out of the earth. Poseidon was essentially the presiding deity over fishermen, and was on that account, more particularly worshipped and revered in countries bordering on the sea-coast, where fish naturally formed a staple commodity of trade.
He was supposed to vent his displeasure by sending disastrous inundations, which completely destroyed whole countries, and were usually accompanied by terrible marine monsters, who swallowed up and devoured those whom the floods had spared. It is probable that these sea-monsters are the poetical figures which represent the demons of hunger and famine, necessarily accompanying a general inundation.
Poseidon is generally represented as resembling his brother Zeus in features, height, and general aspect; but we miss in the countenance of the sea-god the kindness and benignity which so pleasingly distinguish his mighty brother. The eyes are bright and piercing, and the contour of the face somewhat sharper in its outline than that of Zeus, thus corresponding, as it were, with his more angry and violent nature. His hair waves in dark, disorderly masses over his shoulders; his chest is broad, and his frame powerful and stalwart; he wears a short, curling beard, and a band round his head.
He usually appears standing erect in a graceful shell-chariot, drawn by hippocamps, or sea-horses, with golden manes and brazen hoofs, who bound over the dancing waves with such wonderful swiftness, that the chariot scarcely touches the water. The monsters of the deep, acknowledging their mighty lord, gambol playfully around him, whilst the sea joyfully smooths a path for the passage of its all-powerful ruler.
He inhabited a beautiful palace at the bottom of the sea at Ægea in Euboea, and also possessed a royal residence on Mount Olympus, which, however, he only visited when his presence was required at the council of the gods. His wonderful palace beneath the waters was of vast extent; in its lofty and capacious halls thousands of his followers could assemble. The exterior of the building was of bright gold, which the continual wash of the waters preserved untarnished; in the interior, lofty and graceful columns supported the gleaming dome.
Everywhere fountains of glistening, silvery water played; everywhere groves and arbours of feathery-leaved sea-plants appeared, whilst rocks of pure crystal glistened with all the varied colours of the rainbow. Some of the paths were strewn with white sparkling sand, interspersed with jewels, pearls, and amber. This delightful abode was surrounded on all sides by wide fields, where there were whole groves of dark purple coralline, and tufts of beautiful scarlet-leaved plants, and sea-anemones of every tint.
Here grew bright, pinky sea-weeds, mosses of all hues and shades, and tall grasses, which, growing upwards, formed emerald caves and grottoes such as the Nereides love, whilst fish of various kinds playfully darted in and out, in the full enjoyment of their native element. Nor was illumination wanting in this fairy-like region, which at night was lit up by the glow-worms of the deep. But although Poseidon ruled with absolute power over the ocean and its inhabitants, he nevertheless bowed submissively to the will of the great ruler of Olympus, and appeared at all times desirous of conciliating him. We find him coming to his aid when emergency demanded, and frequently rendering him valuable assistance against his opponents.
At the time when Zeus was harassed by the attacks of the Giants, he proved himself a most powerful ally, engaging in single combat with a hideous giant named Polybotes, whom he followed over the sea, and at last succeeded in destroying, by hurling upon him the island of Cos. These amicable relations between the brothers were, however, sometimes interrupted. Thus, for instance, upon one occasion Poseidon joined Hera and Athene in a secret conspiracy to seize upon the ruler of heaven, place him in fetters, and deprive him of the sovereign power.
The conspiracy being discovered, Hera, as the chief instigator of this sacrilegious attempt on the divine person of Zeus, was severely chastised, and even beaten, by her enraged spouse, as a punishment for her rebellion and treachery, whilst Poseidon was condemned, for the space of a whole year, to forego his dominion over the sea, and it was at this time that, in conjunction with Apollo, he built for Laomedon the walls of Troy.
Poseidon married a sea-nymph named Amphitrite, whom he wooed under the form of a dolphin. She afterwards became jealous of a beautiful maiden called Scylla, who was beloved by Poseidon, and in order to revenge herself she threw some herbs into a well where Scylla was bathing, which had the effect of metamorphosing her into a monster of terrible aspect, having twelve feet, six heads with six long necks, and a voice which resembled the bark of a dog. This awful monster is said to have inhabited a cave at a very great height in the famous rock which still bears her name, and was supposed to swoop down from her rocky eminence upon every ship that passed, and with each of her six heads to secure a victim.
Amphitrite is often represented assisting Poseidon in attaching the sea-horses to his chariot. The Cyclops, who have been already alluded to in the history of Cronus, were the sons of Poseidon and Amphitrite. They were a wild race of gigantic growth, similar in their nature to the earth-born Giants, and had only one eye each in the middle of their foreheads. They led a lawless life, possessing neither social manners nor fear of the gods, and were the workmen of Hephæstus, whose workshop was supposed to be in the heart of the volcanic mountain Ætna.
Here we have another striking instance of the manner in which the Greeks personified the powers of nature, which they saw in active operation around them. They beheld with awe, mingled with astonishment, the fire, stones, and ashes which poured forth from the summit of this and other volcanic mountains, and, with their vivacity of imagination, found a solution of the mystery in the supposition, that the god of Fire must be busy at work with his men in the depths of the earth, and that the mighty flames which they beheld, issued in this manner from his subterranean forge.
The chief representative of the Cyclops was the man-eating monster Polyphemus, described by Homer as having been blinded and outwitted at last by Odysseus. This monster fell in love with a beautiful nymph called Galatea; but, as may be supposed, his addresses were not acceptable to the fair maiden, who rejected them in favour of a youth named Acis, upon which Polyphemus, with his usual barbarity, destroyed the life of his rival by throwing upon him a gigantic rock.
The blood of the murdered Acis, gushing out of the rock, formed a stream which still bears his name. Triton, Rhoda,and Benthesicyme were also children of Poseidon and Amphitrite. The sea-god was the father of two giant sons called Otus and Ephialtes. When only nine years old they were said to be twenty-seven cubits in height and nine in breadth. These youthful giants were as rebellious as they were powerful, even presuming to threaten the gods themselves with hostilities.
During the war of the Gigantomachia, they endeavoured to scale heaven by piling mighty mountains one upon another. Already had they succeeded in placing Mount Ossa on Olympus and Pelion on Ossa, when this impious project was frustrated by Apollo, who destroyed them with his arrows. It was supposed that had not their lives been thus cut off before reaching maturity, their sacrilegious designs would have been carried into effect. Pelias and Neleus were also sons of Poseidon. Their mother Tyro was attached to the river-god Enipeus, whose form Poseidon assumed, and thus won her love. Pelias became afterwards famous in the story of the Argonauts, and Neleus was the father of Nestor, who was distinguished in the Trojan War.
The Greeks believed that it was to Poseidon they were indebted for the existence of the horse, which he is said to have produced in the following manner: Athene and Poseidon both claiming the right to name Cecropia (the ancient name of Athens), a violent dispute arose, which was finally settled by an assembly of the Olympian gods, who decided that whichever of the contending parties presented mankind with the most useful gift, should obtain the privilege of naming the city. Upon this Poseidon struck the ground with his trident, and the horse sprang forth in all his untamed strength and graceful beauty. From the spot which Athene touched with her wand, issued the olive-tree, whereupon the gods unanimously awarded to her the victory, declaring her gift to be the emblem of peace and plenty, whilst that of Poseidon was thought to be the symbol of war and bloodshed. Athene accordingly called the city Athens, after herself, and it has ever since retained this name. Poseidon tamed the horse for the use of mankind, and was believed to have taught men the art of managing horses by the bridle.
The Isthmian games (so named because they were held on the Isthmus of Corinth), in which horse and chariot races were a distinguishing feature, were instituted in honour of Poseidon. He was more especially worshipped in the Peloponnesus, though universally revered throughout Greece and in the south of Italy.
His sacrifices were generally black and white bulls, also wild boars and rams.
His usual attributes are the trident, horse, and dolphin. In some parts of Greece this divinity was identified with the sea-god Nereus, for which reason the Nereides, or daughters of Nereus, are represented as accompanying him.
The Romans worshipped Poseidon under the name of Neptune, and invested him with all the attributes which belong to the Greek divinity. The Roman commanders never undertook any naval expedition without propitiating Neptune by a sacrifice.
His temple at Rome was in the Campus Martius, and the festivals commemorated in his honour were called Neptunalia.
From: Berens, E.M. The Myths and Legends of Ancient Greece and Rome. New York: Maynard, Merril, & Co., 1880. Text in the public domain.