Poseidon was the brother of Zeus, and beyond their famous tempers and ability to conjure storms the two seemed to share a very particular trait.
Both gods were famous, or infamous, for their many affairs. By seduction or by force, they each had relationships with many nymphs, princesses, and even Olympian goddesses.
Of course, both were married and had several children with their wives. Poseidon however, was like his brother in that most of the children he had with his wife Amphitrite were minor gods who had little significance in mythology.
In Poseidon’s case he had only one son within his marriage. Triton was a merman who served as his father’s herald and assistant.
Much more famous, for both brothers, were those children born from their many affairs. Like Zeus, Poseidon was the father of many heroes and kings of the Greek world.
Many sources identify different figures as children of Poseidon and his various mistresses. Altogether, dozens of names are listed among his supposed children.
Many of the sons of Poseidon were legendary kings who were regarded as the founders of their respective states. Often there was no specific myth connected to this claim, only family genealogies or local legends that claimed their forefathers were born to the great sea god.
Poseidon was even the father of some non-human children. Often associated with horses, his sons sometimes took the form of his sacred animal.
The god of the sea was even the father to a few giants. The Cyclopes of the Odyssey were sons of Poseidon, and the hero earned the god’s enmity by blinding Polyphemus early in his travels.
Poseidon’s most well-known sons, however, were great hero. While most of Greece’s legendary heroes were his nephews, Bellerophon and Theseus claimed Poseidon as their father.
His mother was the Corinthian queen Eurynome. There was some dispute over whether he was truly the son of a god, though, as some sources claimed that Eurynome’s human husband King Glaucus was actually his father.
Less in doubt was that Poseidon was the son of Theseus. In fact, many of Theseus’s legends involve him proving his divine origin to those who doubted his claim.
Theseus was said to have miraculously been born to Aethra with both Poseidon and her human paramore, the king of Athens, as his fathers. This dual parentage gave Theseus his heroic nature but also provided the childless King Aegeus with an heir.
Theseus was raised by his mother but traveled to his human father’s lands as a teenager. He encountered six underworld guardians on his journey but proved his heroism by slaying them each.
When he arrived in Athens, the city was under the control of King Minos of Crete. The Cretan king had demanded that young Athenians be sent to his city as sacrifices to the Minotaur that was locked in the Labyrinth below Knossos.
Theseus volunteered to take one of the places and, with the help of Minos’s daughter Ariadne, killed the Minotaur and found his way back out of the maze-like dungeon.
Theseus had many other myths, including his trip to the underworld in an attempt to abduct Persephone, but was often remembered as one of the great founding kings of Athens.
He took his mortal father’s place as king and was remembered in Athenian history as a great reformer.
It is easy even at a casual glance to see the similarities between the sons of Zeus and Poseidon. Both fathered many minor gods but, from several affairs, were also the fathers of kings and heroes.
Their heroic sons, too, share many common traits. Theseus and Heracles both undertook similar labors to prove their worth, journeyed to the underworld, and were known for sharing their fathers’ love of women.
The stories of their sons tie Zeus and Poseidon together as gods of a similar type. They were not only brothers, but they came from the same general archetype of god kings.
While Zeus was the king of all the Olympians, including his brother, Poseidon’s power was nearly equal. He ruled over the sea just as Zeus did the sky and, together with their brother Hades, they shared dominion over the earth.
Both were often depicted as older men with the full white beards that signified wisdom and experience. In fact, without attributes like Poseidon’t trident on display, images of the two gods were practically interchangeable.
Poseidon and Zeus may have come from a common archetype that, reflecting the environment of the Greek world, was split into rulers over two domains. The sea, being so important to the Greek world, was a realm of its own that had its own god-king in Poseidon.
The stories of their sons, therefore, can be seen as further evidence that Poseidon and Zeus were linked by a common origin. While the names and details of the stories differed, the two gods’ families were so similar as to suggest the stories may have been interchangeable at one time.
As a second king in the hierarchy of Olympus, Poseidon also provided an alternative way for human cities and rulers to trace their lineage.
It was common for ruling families to claim that their dynasties and kingdoms had been founded by the son or grandson of a god. This added legitimacy to their claim to power and provided them with a patron god who could be expected to favor them.
The descendents of Zeus founded many of the cities and states of the Greek world. He was the common ancestor of the Argive genealogy, which traced the ruling family of Argos through their intermarriage with other kings and the establishment of many kingdoms in both the Greek world and Africa.
Descent from Poseidon provided an alternative to Zeus’s many children. When so many cities were ruled by families who claimed to have Zeus as a forefather, a link to Poseidon differentiated their neighbors.
In the case of Athens, it also strengthened legendary ties to the god. Poseidon and Athena had once competed for patronage of the city, and the establishment of his son as its king kept Poseidon as an official sponsor of Athens.
Like his brother, Zeus, Poseidon had many sons. Some were born to goddesses, others to mortal women, and a few were even the children of monsters.
Many of Poseidon’s sons were minor gods, such as his only son with his wife, Triton. More were said to be founding kings of cities throughout the Greek world.
His role as the ancestor of kings was one he shared with his brother. Such a claim gave a ruling family a stronger claim to power and gave the city a sense of protection.
He was also the father of the cyclops encountered by Odysseus.
A few of Poseidon’s children took the form of horses. Most notable of these was Pegasus, who was famously ridden by another possible son of Poseidon, the hero Bellerophon.
His most famous son, however wasTheseus. The Greek hero was the son of both Poseidon and the king of Athens, making him both blessed by the gods and a legitimate heir to the kingdom.
Theseus is most well-known for killing the Minotaur and freeing his city from Cretan rule. He became the king of Athens in the most famous example of a royal line claiming descent from Poseidon.
The similarities between Poseidon’s sons and lovers and those of his brother may point to a common ancestor between them. In the pre-Greek era, the two kingly gods may have been a single entity who was the ancestor of all human kings and heroes.