The Curious Origins of the Phrase ‘Achilles Heel’

In this week’s Dispatches from The Secret Library, Dr Oliver Tearle explores the meaning and history of a famous phrase

We’ve doubtless all heard the phrase ‘Achilles heel’. It is used to refer to an otherwise strong person’s one weak spot, and references a story from Greek mythology concerning the great hero Achilles. Here’s a brief summary of the Achilles story:

The goddess Thetis conceived Achilles with Peleus, King of Phthia. In order to make her son invincible and invulnerable, Thetis dipped her young son in the river Styx, the river of the Underworld. The only part of Achilles’ body which remained vulnerable was his heel: because Thetis was holding the infant boy by that part of his body, it wasn’t submerged in those magic waters. So, Achilles was invulnerable in battle – but his heel remained vulnerable to attack.

The first great epic poem in Western literature, Homer’s Iliad, concerns the Trojan War between the Greeks (although they’re not referred to as such) and the Trojans, following the abduction of Helen of Troy by the Trojan prince Paris. (‘Ilium’ is another name for Troy.)

But although the Iliad is, as Homer announces at the beginning of the poem, about ‘the wrath of Achilles’, the Greek hero doesn’t die in the Iliad, nor is his heel his one vulnerable spot. (Surprisingly, a number of the most famous incidents from the myth of the Trojan War don’t appear in Homer’s poem: there’s no Trojan Horse either.) Indeed, at one point in the Iliad, Achilles is wounded in the elbow:

Thus did he defy him, and Achilles raised his spear of Pelian ash. Asteropaeus failed with both his spears, for he could use both hands alike; with the one spear he struck Achilles’ shield, but did not pierce it, for the layer of gold, gift of the god, stayed the point; with the other spear he grazed the elbow of Achilles’ right arm drawing dark blood, but the spear itself went by him and fixed itself in the ground, foiled of its bloody banquet.

What’s more, Achilles’ death doesn’t actually occur in Homer’s poem. The whole of the Iliad covers only a few weeks in the final stage of the war – and twenty-two of the twenty-four books which make up the poem cover the events of just a few days. This allows Homer to focus in detail on the individual characters in the war. But although we learn much about Achilles’ wrath, heroism, strength, and comradeship, we learn nothing about the most famous thing now associated with him, via the idiom of the ‘Achilles heel’. That appears to have been a later invention, by other writers.

So, the account of Achilles’ death was left up to other ancient Greek poets and mythmongers. But even outside of Homer’s poem, Achilles’ heel wasn’t always depicted as his … well, his Achilles heel. In some depictions of the Greek hero in classical art, he is shown dying from a wound to his torso, rather than his heel. In one later myth, Achilles fell so in love with Priam’s daughter, Polyxena, that he agreed that he would defect to the Trojan side if Priam would agree to a marriage between Achilles and Polyxena. Priam accepted, but when Achilles turned up at the temple of Apollo Thymbrius to ratify the betrothal in the eyes of the gods, Paris – concealed behind the statue of Apollo – shot Achilles with an arrow.

But perhaps the most famous account of Achilles’ death involves his heel, and sees the hero dying in battle against the Trojans. When Achilles ignored the god Apollo’s orders for him to withdraw his army, Paris – his arrow guided by Apollo – shot Achilles in the heel, the one part of him that remained vulnerable, and the hero died.

There were other epic poems, besides the Iliad, which were written about Achilles. Perhaps the most notable of these was Statius’ unfinished poem the Achilleid which, if completed, would have depicted Achilles’ life, right up to his death at Troy. Unfortunately, only about one and a half books were completed before Statius’ death. The bits he did get round to writing focus on Achilles’ early life, including, amusingly, an episode in which the hero’s mother disguised him as a girl on the island of Scyros before he joined the Greek expedition against Troy.

In English, the use of the phrase ‘Achilles heel’ dates from the seventeenth century. Although the earliest citation in the Oxford English Dictionary is dated 1705, this is the date of publication, not composition. The earliest citation in the OED is from the seventeenth-century Anglo-Irish poet John Denham (1614/15-69), who’s best known for the long poem Cooper’s Hill (1642). Denham also, however, gave us this couplet:

Leave then, said he, th’ invulnerable Keel,
We’ll find they’re feeble, like Achilles Heel.

Not perhaps the finest two lines in English verse, but they are among the earliest to feature the idiom ‘Achilles heel’, in the form of a simile to show that the phrase was already employed in extended use (i.e. not just in literal reference to the mythical character from the Trojan War).

As an expression meaning one’s weak spot, i.e. talking of ‘an Achilles heel’ rather than merely something that might be likened to Achilles’ heel, the use of ‘Achilles heel’ seems only to have taken off in the nineteenth century. In 1810, the Romantic poet Samuel Taylor Coleridge wrote of ‘Ireland, that vulnerable heel of the British Achilles!’ And the idiom has firmly been with us since.

The ‘Achilles tendon’, meanwhile, had already been so named: in 1693, the Flemish anatomist Philip Verheyen, writing in his Corporis Humani Anatomia, described the tendon as ‘the cord of Achilles’.

Oliver Tearle is the author of The Secret Library: A Book-Lovers’ Journey Through Curiosities of History, available now from Michael O’Mara Books, and The Tesserae, a long poem about the events of 2020.

Image: via Wikimedia Commons.