The Amazing Origin of the Story of Achilles’s Heel

We all know the story of “Achilles’s heel.” The story you probably learned in school goes like this: When Achilles was a baby, his mother Thetis dipped him in the river Styx to make him immortal and impervious to all wounds—except she held him by his heel, meaning his heel was the only part of him that was vulnerable. Many years later, near the end of the Trojan War, the Trojan prince Paris shot him in the heel with an arrow guided by the god Apollon and killed him.

This story is the source of our English phrase “Achilles’s heel,” which is often used to refer to a single fatal weakness in something that is otherwise seen as invincible. It may come as a surprise to some people that this story is not actually found in the Iliad or in any other work of classical Greek literature from before the Roman Era. In fact, in the Iliad, Achilles isn’t even invulnerable at all!

Not invulnerable in the Iliad

There is no mention anywhere in the Iliad of Achilles being invulnerable everywhere except for his heel. In fact, we know that Achilles is not invulnerable in the Iliad because, in Book Twenty-One, the ambidextrous Trojan warrior Asteropaios actually wounds Achilles on the forearm and Achilles is explicitly described as bleeding out. Here is the Greek text of the Iliad, Book Twenty-Two, lines 166 through 167:

“τῷ δ᾽ ἑτέρῳ μιν πῆχυν ἐπιγράβδην βάλε χειρὸς
δεξιτερῆς, σύτο δ᾽ αἷμα κελαινεφές:”

Here is my own translation:

“But, with the other [spear], he [i.e. Asteropaios] grazingly struck him on the forearm of his right arm, and black blood spurted forth.”

In other words, in the Iliad, Achilles can be cut and he can bleed; the reason why he is so fearsome is not because his skin is magically impervious, but rather because he is such an awesome fighter.

ABOVE: Engraving by Johann Balthasar Probst (lived 1673 – 1748) showing Achilles fighting Trojan warriors by the river Skammandros, which is where he fights Asteropaios

Hektor’s prediction of Achilles’s death in the Iliad

Contrary to popular belief, the Iliad does not describe the entire story of the Trojan War. The poem actually ends with the funeral of Hektor. When the poem ends, Achilles is still alive and no one has even thought of the idea of the Trojan Horse. Nonetheless, in Book Twenty-Two, with his dying breath, Hektor prophesies that Achilles will be slain by his brother Paris, working in cooperation with the god Apollon. Here is what Hektor says in Book Twenty-Two, lines 424 through 429 of Robert Fitzgerald’s translation:

“I see you now for what you are. No chance
to win you over. Iron in your breast
your heart is. Think a bit, though: this may be
a thing the gods in anger hold against you
on that day when Paris and Apollo
destroy you at the Gates, great as you are.”

This is all the Iliad tells about the manner of Achilles’s death. Notice how vague this prediction is. Hektor never says exactly how Paris and Apollon are going to kill Achilles; he merely says that they are going to do it at the gates of Troy.

We can easily infer from Hektor’s prophecy that Paris is probably going to kill Achilles with an arrow, since, as I discuss in this article from May 2020, the main weapon used by Paris throughout the Iliad is a bow. Furthermore, we also know that Apollon was the god of archery. There’s nothing here that even remotely suggests Paris is going to kill Achilles by shooting him specifically in the heel, though.

ABOVE: Achilles Slays Hector, painted between c. 1630 and c. 1635 by the Flemish Baroque painter Peter Paul Rubens

The origin of the story about Thetis dipping Achilles in the river Styx

If we look at other ancient sources written after the Iliad, we can actually trace the development of the story about Thetis dipping Achilles in the river Styx. The Aigimios was an epic poem that was popularly attributed in antiquity to the poet Hesiodos of Askre, who lived sometime in around the late eighth century BC or early seventh century BC. It has not survived to the present day, but we know a little bit about it from references in surviving sources.

A scholion, or ancient scholarly commentary, on Book Four of the epic poem Argonautika, which was written by the Hellenistic Greek poet Apollonios of Rhodes (lived c. 295 – c. 215 BC), notes that the Aigimios told a story about how Thetis tested her offspring to see if they were immortal by throwing them into a cauldron of boiling water.

Naturally, all the children she tested in this manner died because they were boiled alive. When she tried to dunk Achilles into the cauldron of boiling water, though, her husband Peleus, Achilles’s father, heroically intervened to stop her, thereby saving Achilles’s life. Here is what the scholiast says, as translated by Hugh G. Evelyn-White:

“The author of the Aigimios says in the second book that Thetis used to throw the children she had by Peleus into a cauldron of water, because she wished to learn where they were mortal . . . And that after many had perished Peleus was annoyed, and prevented her from throwing Akhilleus into the cauldron.”

This version of the story seems to be the oldest. Over time, though, ancient storytellers seem to have reworked the story to make it less gruesome.

ABOVE: Photograph from Wikimedia Commons of a second-century AD Roman fresco from the House of Theseus in the Paphos National Park depicting Thetis with a cauldron. One of her attendants, who is labeled “Anatrophe,” which means “Upbringing,” is holding the infant Achilles. Another attendant, who is labeled “Ambrosia,” is holding a pitcher of water for the cauldron.

Apollonios of Rhodes’s version

Apollonios of Rhodes gives a drastically different account of the incident in his Argonautika that frames the whole situation as a big misunderstanding. According to Apollonios, Thetis actually wanted to make Achilles immortal, so, at night, she would put him in the fire to burn away his mortal flesh and, during the day, she would anoint him with ambrosia.

Unfortunately, one night, Achilles’s father Peleus woke up and saw Thetis burning their son in the fire. He foolishly misunderstood what she was doing and screamed, causing Thetis to drop Achilles on the ground and flee. Apollonios writes, as translated by Richard Hunter:

“In the dead of night she [i.e. Thetis] would constantly put burning fire around his [i.e. Achilles’s] mortal flesh, and during the days she anointed his tender limbs with ambrosia, to make him immortal and to keep hateful old age away from his body. But Peleus leapt from his bed and saw his dear son gasping in the flames; at this sight he let out a terrible scream—foolish man! When Thetis heard, she snatched out the crying baby and dropped him to the floor and, in a form like a breath of wind, she sped from the house like a dream and leapt into the sea in her anger. After this, she did not return.”

In this version of the story, we see the beginnings of the story that we know today. Here, Thetis is trying to make Achilles immortal, but she fails due Peleus’s misunderstanding.

ABOVE: Dutch illustration by J. Alexander Janssensnaar from c. 1700 showing Thetis sticking the infant Achilles in the fire

Statius’s version

The story about Thetis dipping the infant Achilles in the river Styx to make him immortal is first attested in the Achilleid, an incomplete epic poem about Achilles written in Latin by the Roman poet Publius Papinius Statius (lived c. 45 – c. 96 AD). In the poem, Thetis mentions dipping Achilles in the waters of the river Styx as an infant to make him immortal several times and, at one point, she laments that she did not make him completely immortal.

Statius doesn’t say anything specific about Achille’s heel being the only vulnerable part of him, though, nor does he say that Paris killed him by shooting him in the heel. In other words, Statius gives us one part of the now-familiar story, but he doesn’t give us the whole thing.

Furthermore, even after Statius, the story about Thetis putting Achilles in the fire and anointing him with ambrosia seems to have remained by far the more common story. For instance, The Library of Pseudo-Apollodoros, a Greek mythographic composition written in around the second century AD or thereabouts, tells the exact same story that is told in Apollonios of Rhodes’s Argonautika. The Library 3.171 reads as follows, as translated by Stephen M. Trzaskoma:

“When Thetis had Peleus’s baby, she wanted to make it immortal. So unbeknownst to Peleus, at night she would hide it in the fire and destroy the mortal part that came from his father. By day she would rub ambrosia on him. When Peleus spied her and saw his son squirming in the fire, he gave a shout. Prevented from carrying out her plan, Thetis went off to the Nereids, abandoning her son in his infancy.”

After the collapse of the western Roman Empire, however, Greek texts became less commonly available in western Europe, as did knowledge of the Greek language. As a result, educated people in western Europe gradually came to rely on sources written in Latin for information about mythology. Thus, Statius’s version eventually became the best-known version in western Europe.

ABOVE: Thetis Immerses Her Son Achilles in the Waters of the River Styx, painted by Antoine Borel (lived 1743 – 1810)

The origin of the story of Paris shooting Achilles in the heel

It is hard to say at what point the story of Paris shooting Achilles specifically in the heel (or, more strictly, the ankle) arose. None of the surviving early Greek sources specify exactly where Paris shot Achilles. There are a handful of early Greek artworks that some scholars have interpreted as evidence that the story of Paris shooting Achilles in the heel may have existed as early as the sixth century BC, but these are highly ambiguous.

A lost Chalkidian black-figure amphora dated to around the middle of the sixth century BC shows the fallen Achilles lying on the ground with an arrow through his ankle. Achilles is clearly labeled, so we know it is definitely supposed to be him. There is another arrow sticking out of his flank, though, which suggests that, in the version of the story represented in the amphora, Achilles was first shot in the ankle to prevent him running and then shot in the side, killing him.

An Etruscan black-figure amphora dated to the late sixth century BC shows Paris about to shoot a warrior, who is thought to be Achilles, from behind, while he is fighting with another warrior. Paris is aiming relatively low, but he seems to be aiming for Achilles’s lower back leg, not his ankle. Furthermore, this may represent only Paris’s first shot, meaning he may be about to shoot Achilles in the leg and then shoot him again in the torso.

An Attic red-figure vase painting from the fifth century BC shows an archer on the left shooting an arrow, which is guided by Apollon, at the lower leg of a warrior standing on right. The figures are not labeled, though, so it is hard to tell if the warrior who is being shot at is even supposed to be Achilles.

Furthermore, the archer in the vase painting already has a second arrow loaded in his bow and he is apparently about to shoot the warrior again, meaning we may be seeing a similar scenario to the one depicted in the Chalkidian amphora, in which Paris first shoots Achilles in the ankle to prevent him from running and then shoots him in the side to kill him.

There are a number of other depictions of unlabeled warriors with arrows in their lower legs and ankles that some have guessed may represent Achilles, but, without labels, we can’t be sure that the warriors in these depictions actually are Achilles and, in most cases, we can’t be sure that the warriors in these depictions are actually dying.

ABOVE: Reproduction based on a photograph from 1927 of a scene from a now-lost Chalkidian black-figure vase painting showing the dead Achilles lying on the ground with one arrow through his ankle and another arrow through his side

The earliest reference in a written source to Paris shooting Achilles specifically in the heel comes from the epitome of the final portion of Pseudo-Apollodoros’s Bibliotheke, which states in section 5.3, as translated by Trzaskoma:

“Achilles also chased the Trojans, and near the Scaian Gates he was shot in the ankle with an arrow by Alexander and Apollo.”

The Bibliotheke makes no mention of Paris shooting Achilles anywhere other than the ankle, so it can be presumed that, in the Bibliotheke‘s version, the shot to the ankle is what kills him.

The Posthomerika, an epic poem composed by the Greek poet Kointos of Smyrna in around the late fourth century AD or thereabouts, also describes Achilles as being shot in the ankle. The description of Achilles’s death in Book Three of the Posthomerika reads as follows, as translated by Arthur S. Way:

“From mortal sight he vanished into a cloud,
and cloaked with mist a baleful shaft he shot
which leapt to Achilles’s ankle: sudden pangs
with mortal sickness made his whole heart faint.
He reeled, and like a tower he fell, that falls
smit by a whirlwind when an earthquake cleaves
a chasm for rushing blasts from underground;
so fell the goodly form of Aeacus’s son.”

While it is difficult to say at what point this story emerged, it is easy to imagine how it might have arisen. One of Achilles’s main epithets in the Iliad is ποδώκης (podṓkēs), which means “swift-footed,” and, in Book Eleven of the Iliad, Paris shoots the Greek warrior Diomedes—who is similar to Achilles in a lot of ways—in the foot.

I reckon that, at some point, someone probably remembered the scene of Paris shooting Diomedes in the foot and imagined Paris doing the same thing to Achilles. We can imagine, based on the Chalkidian amphora, that, in earlier versions of the story, Achilles is first shot in the ankle and then in the flank. Eventually, at some point presumably after Statius but before the composition of Pseudo-Apollodoros’s Bibliotheke the second century AD, someone tied it all back to the story from Statius about Thetis dipping Achilles in the waters of the river Styx. Thus, the legend as we know it today was born.

It’s amazing how the mythological tradition is constantly evolving. There are actually lots of other things that people think are in the Iliad that actually aren’t. For instance, even though seemingly every single adaptation of the Trojan War from the past twenty years includes a scene where Achilles marches up to the gates of Troy and calls Hektor out of the city to fight him, this scene actually isn’t in the Iliad either.