A man named Diomedes once owned horses that could not be tamed. Not because they were wild, but because they had already eaten their previous grooms. The eighth labor of Heracles was not a monster hunt. It was a horse theft. And the horses themselves were the monsters.
The Mares of Diomedes were four man-eating horses owned by the Thracian king Diomedes, captured by Heracles as his eighth labor. Their names vary across sources, but the most consistent list is Podargos (swift-footed), Lampon (shining), Xanthos (yellow), and Deinos (terrible). These were not ordinary warhorses. They were fed human flesh by their master, and they became what they ate.
Who Named the Mares, and Why the Names Matter
The earliest surviving list of the mares’ names comes from the Library of Apollodorus (2nd century BCE), a Greek mythographer who compiled the labors of Heracles into a single narrative. Apollodorus names four horses: Podargos, Lampon, Xanthos, and Deinos. The Roman poet Hyginus (1st century BCE), in his Fabulae, offers a slightly different set: Podargos, Lampon, Xanthos, and Strymon. The fourth name changes, but the pattern holds.
Each name is a description. Podargos means “swift-footed” (from pous, foot, and argos, bright or swift). Lampon means “shining” or “bright.” Xanthos means “yellow” or “golden.” Deinos means “terrible” or “fearsome.” Strymon refers to a river in Thrace, possibly the horse’s origin place.
These names are not decorative. In Greek myth, naming a thing was an act of definition. The horses were named for what they did or what they were made of. A horse named “terrible” was not being poetic. It was a warning.
The Eighth Labor: What Actually Happened
Heracles was sent to King Eurystheus of Tiryns as a servant, bound to perform twelve labors. The eighth was to bring back the mares of Diomedes, who ruled the warlike tribe of the Bistones in Thrace. Diomedes kept his horses tethered with bronze chains, fed them on the flesh of unsuspecting strangers, and used them as a tool of terror.
Heracles arrived with a small crew of volunteers, including Abderos, a young man from Opus. The plan was simple: overpower the grooms, steal the horses, and sail away. Heracles succeeded in capturing the mares and drove them toward the coast. But Diomedes and his army pursued.
Here the accounts diverge. In the version told by Diodorus Siculus (1st century BCE), Heracles turned the horses loose on Diomedes himself. The king was devoured by his own animals. In Euripides’ play Alcestis (438 BCE), Heracles kills Diomedes in battle and feeds his body to the mares. Either way, the horses ate their master.
Once the king was dead, the horses became manageable. Heracles drove them to Tiryns, where Eurystheus dedicated them to Hera. The goddess, according to Pausanias (2nd century CE), allowed the horses to breed on the plain of Argos. Their descendants were said to have been used in the Trojan War, pulling the chariot of the Greek hero Eumelos.
The human cost was Abderos. He was left to guard the horses while Heracles fought Diomedes, and the mares tore him apart. Heracles founded the city of Abdera in his honor, a city that later produced the philosopher Democritus. The name of a devoured boy became a city of thinkers.
What the Horses Symbolized
The Mares of Diomedes are not a story about horses. They are a story about what happens when power is fed on cruelty.
In Greek thought, horses were symbols of nobility, speed, and controlled passion. The chariot was a mark of civilization. The mares invert this entirely. They are horses that have been turned into weapons by a king who fed them human flesh. They are nature corrupted by nurture. Diomedes did not tame them. He poisoned them.
The labor itself is a study in inversion. Heracles does not kill the monster. He makes the monster kill its creator. The king who fed others to his horses is fed to them instead. The lesson is not subtle: what you feed will feed on you.
In later esoteric traditions, particularly in the Hermetic and alchemical readings of the labors, the mares represent the untamed appetites of the soul. The eighth labor is the work of redirecting raw desire. The horses cannot be destroyed, only fed something else. Once the corrupt master (Diomedes) is removed, the horses become usable. They pull chariots. They serve.
The Names in Practice: How You Spoke to Each
If you worked with these names in a ritual context, you would not treat them as interchangeable. Each name carries a distinct quality.
Podargos (swift-footed) is the horse of speed, of sudden movement, of the impulse that acts before thought. In a working, you would call on Podargos when you need to move fast, to break inertia, to leave a situation before it turns. But you would not call Podargos lightly. Speed without direction is destruction.
Lampon (shining) is the horse of visibility, of being seen, of the light that draws attention. Lampon is the name for work that requires exposure: revealing a hidden truth, making yourself known, stepping into the open. The danger is overexposure. Lampon burns.
Xanthos (yellow, golden) is the horse of material wealth, of the earth’s gifts, of the color of ripened grain and amber. Xanthos is the name for prosperity work, for grounding, for the slow accumulation of value. But gold attracts thieves. Xanthos must be guarded.
Deinos (terrible) is the horse of fear, of the awe that precedes destruction. Deinos is the name you speak when you need to terrify an enemy, to break a resistance, to make something retreat. It is the name of last resort. Once Deinos is called, you cannot call it back.
Strymon (the river) appears in Hyginus as a replacement for Deinos. If you work with Strymon, you work with boundary, with the river that separates the living from the dead, the tame from the wild. Strymon is the horse of thresholds.
How the Mares Compare to Other Mythological Horses
The Mares of Diomedes belong to a family of dangerous horses in Greek myth, but they are not the same as the others.
Sleipnir, the eight-legged horse of Odin in Norse myth, is a horse of passage between worlds. He is not dangerous by nature. He serves his rider. The mares serve no one until their master is dead.
Pegasus, the winged horse born from Medusa’s blood, is a horse of inspiration and flight. He carries the hero Bellerophon until Bellerophon’s hubris causes him to fall. Pegasus is a test of character. The mares are a test of survival.
Arion, the horse of Adrastus, could speak human language and was born from a union of Poseidon and Demeter. Arion is a horse of prophecy and counsel. The mares do not speak. They eat.
The horses of Achilles, Balios and Xanthos (the same name as one of Diomedes’ mares), were immortal and could prophesy. Xanthos tells Achilles that his death is near. The mares of Diomedes do not warn. They consume.
The difference is agency. Balios and Xanthos are allies. Pegasus is a gift. The mares of Diomedes are tools that have become weapons. They are not partners. They are consequences.
Common Misconceptions
“There were only two mares.” Some modern retellings reduce the number to two, likely confusing the Mares of Diomedes with the horses of Achilles. The ancient sources consistently name four. Apollodorus, Hyginus, and Diodorus Siculus all list four. The number is not debated in the primary texts.
“Heracles tamed them by feeding them Diomedes.” This is partially correct but oversimplified. Heracles did not tame the horses by feeding them their master. He killed Diomedes, fed the body to the mares, and then the horses became manageable. The feeding was not the taming method. It was the removal of the corrupting influence.
“The mares were immortal.” No ancient source claims the mares were immortal. They were mortal horses that had been fed human flesh. Their descendants appear in later Greek history, pulling chariots in the Trojan War. Immortal horses in Greek myth are rare and usually named as such (like the horses of Achilles).
“The names are interchangeable.” They are not. Each name has a specific meaning, and the variations across sources (Deinos vs. Strymon) represent different traditions, not carelessness. A practitioner working with these names should choose one consistent source and work within that frame.
FAQ
Were the Mares of Diomedes real horses? No. They are mythological figures from Greek heroic legend, first recorded in the 8th century BCE by Homer (who mentions the labor in the Iliad without naming the horses) and later detailed by Apollodorus and others.
Why did Heracles need to capture the mares? The eighth labor was assigned by King Eurystheus as part of Heracles’ penance for killing his own family. The labors were designed to be impossible. The mares were one of several monsters and challenges that Heracles had to overcome.
Can the mares’ names be used in modern occult practice? Yes. Some practitioners of Hellenic reconstructionist traditions and ceremonial magic use the names as symbols of specific forces (speed, visibility, wealth, fear). The names are treated as invocations of the qualities they represent, not as entities to be summoned.
What happened to the mares after the labor? According to Apollodorus, Eurystheus dedicated the mares to Hera, who allowed them to breed. Their offspring were used in the Trojan War. Pausanias records that the mares’ descendants were still known in the Argolid in the 2nd century CE.
The Horses Still Run
The Mares of Diomedes are not a footnote in a hero’s career. They are a warning about the cost of cruelty, the danger of feeding power on violence, and the possibility of redemption after the corrupting influence is removed. The names survive because they name something real: the part of us that could become what we feed it.
For more on the labors of Heracles and the creatures he faced, see our guide to mythological monsters. The names of the mares also appear in the Greek magical papyri, where they are invoked in binding spells. And for the full context of the eighth labor, read our article on Heracles and the cycle of atonement.
The horses are still running. The question is who holds the reins.