Thetis

Thetis (THEE-tis), in Greek Θέτις, the silver-footed sea-goddess (argyropeza, "silver-footed," is Homer's tireless epithet for her), is the chief and most honoured of the fifty Nereids — the sea-nymph daughters of the old sea-god Nereus and the Oceanid Doris — and one of the most important minor divinities in all of Greek myth. Though she is counted among the nymphs, Homer calls her plainly a goddess (thea), and she moves through the highest company of heaven: she is owed favours by Zeus himself, she commands the workshop of Hephaestus, and she is the mother of Achilles, the greatest of the Greek heroes at Troy. Around her turns one of the hinges of the whole mythology, for it was her marriage that set in motion the events that led to the Trojan War, and her son whose short, blazing life is the subject of the Iliad.

Thetis's tragedy is written into her from the start by a prophecy. It was foretold — by Themis, or in another telling by Prometheus, who alone knew the secret — that Thetis was fated to bear a son mightier than his father. Both Zeus and Poseidon had desired her; but when they learned of the prophecy, the sea-goddess who might have been queen of Olympus became instead a danger too great to touch, for a son greater than Zeus would overturn the order of the world exactly as Zeus had overturned Cronus. So the gods did the one thing that would neutralise the doom: they married the immortal Thetis, against her will, to a mortal man, Peleus king of Phthia, so that her too-great son would be born mortal and would die. That son was Achilles — and the whole grief of Thetis is that she was made to bear a hero she was fated to bury.

She is, above all, the archetype of the divine mother caught in a mortal's doom: the goddess who tried by every means to make her child immortal and failed, who knew from his birth the two fates set before him and could not turn either aside, who rose from the sea again and again through the Iliad to help him and to weep for him, who fetched him god-forged armour from Hephaestus, and who at the last led her sister Nereids up out of the water to mourn over his body on the shore. To tell the story of Thetis is to tell the story of a love that immortality could not protect and prophecy could not spare — the silver-footed goddess who gave the sea's greatest gift, a hero, and paid for it with the one grief the deathless were never meant to feel.

Daughter of the Old Man of the Sea

Thetis is one of the Nereids, the fifty (in some counts more) daughters of Nereus, the truthful and shape-shifting "Old Man of the Sea," and of Doris, a daughter of Oceanus. Hesiod names the Nereids in the Theogony (240–264) — a shining catalogue of sea-nymphs whose names sound the moods and gifts of the calm sea — and among them Thetis stands out as the greatest, "who beyond all the rest is queenly among them" in the sense the tradition gave her: eldest, chief, and most honoured of her sisters. The Nereids are the gentle, kindly powers of the deep, dancing on the waves and rising to save sailors in distress, and Thetis is their natural leader, the one who summons them from the sea-floor when there is grief to be shared. Her sister Amphitrite became the queen of the sea as the wife of Poseidon; Thetis, by contrast, was fated for a stranger and heavier destiny.

The rescuer of gods — Thetis before the war

Long before she was a mother, Thetis appears in the older myths as a saviour and fosterer of gods, and it is this that gives her such standing among the immortals. Homer has her tell, in the Iliad, how she once rescued Zeus himself: when Hera, Poseidon, and Athena tried to bind the king of the gods in chains and overthrow him, it was Thetis who brought up out of the sea the hundred-handed giant Briareos (Aegaeon) to sit beside Zeus, so that the terrified conspirators drew back and the revolt collapsed. She also sheltered the god Hephaestus when his mother Hera, disgusted by his lameness, flung him from Olympus into the sea: Thetis and her sister-nymph Eurynome caught him and hid him in a cave in the deep, and there for nine years the smith-god made them fine ornaments in gratitude (Iliad 18.394–409) — a kindness the tradition never forgot, and the reason Hephaestus will refuse Thetis nothing. And when the young Dionysus fled in terror from the murderous King Lycurgus, plunging into the sea, it was again Thetis who received the god into her bosom and kept him safe (Iliad 6.135–137). This is the deep grammar of Thetis's power: she is the sea-goddess to whom the gods themselves turn when they fall, and the debts of Zeus and Hephaestus alike will one day be repaid to her son.

The prophecy of the greater son

(Content note: this myth turns on a marriage forced upon an unwilling goddess.) The turning-point of Thetis's whole story is a prophecy. Both Zeus and Poseidon desired her and were rivals for her hand — but there was a secret about Thetis that changed everything. According to Pindar (Isthmian 8) it was Themis, the goddess of divine law, who declared it in the council of the gods; in the version dramatised by Aeschylus and made famous later, it was Prometheus, the Titan who saw ahead, who alone held the secret and traded it for his freedom: that Thetis was destined to bear a son mightier than his father. For any god this was a fatal warning. Zeus had himself deposed his father Cronus, as Cronus had deposed Uranus; a son greater than Zeus would break the succession of heaven and end his reign. So the very quality that made Thetis a desirable bride — the greatness of the son she would bear — made her untouchable to the gods, and the two rivals drew back from her in fear. To dispose of the danger, the gods resolved that Thetis must be married not to an immortal at all but to a mortal man, so that her mighty son would be born subject to death and could never threaten Olympus. The husband they chose was Peleus, the pious king of Phthia in Thessaly and a favourite of the gods.

Peleus and the wrestling-match — winning the shape-shifter

Thetis, an immortal goddess, had no wish to be given to a mortal, and she would not be won without a struggle — for like her father Nereus she had the power of metamorphosis, and could change her shape into anything to escape a suitor's grasp. The gods (Cheiron the wise Centaur, in the usual telling, gave Peleus his counsel) instructed Peleus how to take her: he must catch her, hold on, and never let go, whatever she became. So Peleus lay in wait and seized the goddess on the shore, and Thetis turned in his arms into fire, into water, into a raging lion, into a hissing serpent, into a great slippery cuttlefish that drenched him with ink — one terrifying form after another, fighting to break free. But Peleus, warned and resolute, clung to her through every change and did not loosen his hold, and at last, when she saw she could not escape, Thetis yielded and consented to be his wife. It is one of the classic Greek myths of mastering a shape-shifting sea-power by sheer holding-on (the same pattern by which Menelaus wrestles Proteus, and Heracles the river Achelous), and it made Peleus the only mortal ever to win an unwilling goddess as a bride.

The wedding of Peleus and Thetis, and the apple of discord

The wedding of Peleus and Thetis was the most splendid marriage in all of Greek myth, and its consequences ran to the ends of the mythology. It was held on Mount Pelion, at the cave of the Centaur Cheiron, and — uniquely for the marriage of a mortal — all the gods of Olympus attended, bringing gifts: the immortal horses Xanthus and Balius and a great ashen spear for Peleus, and the Muses sang the wedding-song. But one goddess was not invited: Eris, the goddess of Strife and Discord, deliberately left off the guest-list because she brought quarrel wherever she went. In revenge for the slight, Eris came anyway, and cast among the feasting goddesses a single golden apple inscribed with the words "for the fairest" (kallistēi). At once Hera, Athena, and Aphrodite each claimed it, and their quarrel could not be settled on Olympus — so Zeus sent the three goddesses to be judged by a mortal shepherd on Mount Ida, the Trojan prince Paris. This was the Judgement of Paris: each goddess offered him a bribe, and Paris awarded the apple to Aphrodite, who had promised him the most beautiful woman in the world — Helen, the wife of Menelaus of Sparta. Paris's carrying-off of Helen brought the thousand ships of Greece against Troy, and so the Trojan War itself was born, in the end, out of an uninvited guest at Thetis's wedding. The marriage meant to contain one doom set another, far greater, in motion.

The mother of Achilles — the attempts to make him immortal

From the marriage of Peleus and Thetis was born a single son, Achilles, who would be the greatest warrior of the age and the central figure of the Iliad. Thetis, a goddess who knew her mortal child was fated to die, tried by every art she had to make him immortal, or at least invulnerable — and here the sources give two quite different tellings that should be kept apart.

The older version, told in the poets and in Apollonius of Rhodes (Argonautica 4.869–879), is one of fire and ambrosia: Thetis would anoint the infant Achilles with ambrosia by day and lay him at night in the fire of the hearth, burning away his mortal part to make him deathless like the gods. (The same rite appears in the Homeric Hymn to Demeter, where the goddess does exactly this to the baby Demophon.) But Peleus, waking one night and seeing his son writhing in the flames, cried out in horror — and the ritual, interrupted, failed; enraged and grieved that her work was broken, Thetis abandoned the child and returned to the sea and her Nereid sisters, and Peleus gave the boy to the Centaur Cheiron to raise. This fire-immortalisation is the earlier and more authentically Greek form of the story.

The famous tale of the River Styx and the fatal heel — that Thetis dipped the baby Achilles into the waters of the Styx to make him invulnerable, holding him by the heel, which alone the water did not touch and where alone he could be killed — is a much later telling. It is not in Homer at all (in the Iliad Achilles can be wounded like any man); it appears fully only in the Roman poet Statius (Achilleid 1.269, late 1st century AD) and later writers, and the "Achilles heel" as the site of his death by Paris's arrow is a post-classical elaboration. It has become the version everyone knows, but it should be flagged as late (Statius and after), not the original: the older Greek tradition knew the fire, not the Styx.

Grief and the two fates

Thetis's motherhood is steeped in foreknowledge and sorrow. She knew that a double fate was set before Achilles (Iliad 9.410–416): if he stayed home in Phthia he would live a long and obscure life, but if he went to Troy he would win undying glory and die young. She tried to keep him from the war — in a later story hiding him disguised as a girl among the daughters of King Lycomedes on Scyros, until Odysseus tricked him into revealing himself — but the fate could not be turned, and Achilles chose the short life of glory. Through the Iliad Thetis is the ever-present grieving mother, appearing whenever her son is in pain: she rises from the sea in the very first book when he weeps over the loss of Briseis, and, at his begging, goes up to Olympus to supplicate Zeus — clasping his knees and his chin in the formal gesture of a suppliant — to win the promise that the Greeks will be beaten and slaughtered at their ships until they learn what they lost in dishonouring her son (Iliad 1). It is a mother's terrible prayer, granted, and the deaths of countless Greeks flow from it.

The divine armour, and the mourning of the Nereids

When Achilles' friend Patroclus is killed wearing Achilles' own armour, and the armour is stripped by Hector, Thetis performs her most famous service. She goes to Hephaestus — the smith-god she had once saved from the sea — and he, refusing her nothing, forges through the night a new and glorious suit of divine armour for Achilles: greaves, breastplate, helmet, and above all the great shield, engraved with the whole world of earth and sky, cities at peace and at war, the fields and the dancing-floor and the encircling Ocean (the ekphrasis of the Shield of Achilles fills much of Iliad 18). Thetis carries the god-forged armour down to her son at dawn and lays it gleaming before him, and Achilles arms for the killing of Hector. But when she brings it she comes weeping, for she knows what the sources call the bitter bargain: that her son is now doomed to die soon after Hector, that the armour she brings him is the harness of his own death. And so, in Iliad 18, she gathers her Nereid sisters out of the depths of the sea and they come up onto the shore to mourn with her over the living Achilles as though he were already dead — the sea filled with the lament of the silver-footed goddess and her sisters, keening for the hero not yet fallen.

The death of Achilles and the goddess's last grief

Achilles was killed, as his mother had always known, before the walls of Troy — struck (in the later tradition) in the heel by an arrow from Paris, guided by Apollo. The scene beyond the Iliad, told in the Aethiopis and remembered in the Odyssey (24.47–64), gives Thetis her last and greatest sorrow: she rose from the sea once more with the Nereids and the Muses, and they mourned over the body of Achilles for seventeen days and nights, wrapping him in immortal robes, and the whole Greek host wept with them. In some tellings Thetis snatched her son from the pyre at the last and bore him away to the White Island (Leuke) in the Black Sea, giving him a blessed immortality among the dead heroes — a final, partial victory of the mother who could not save his life but would not wholly lose him to death. The goddess who had been forced to marry a mortal so that her son might die had come, in the end, to the grief she was made to bear: the silver-footed immortal weeping on the shore over the greatest of mortal men.

A goddess more sung than shrined

Thetis was one of those divinities whose place in Greek religion was carried far more by poetry and story than by widespread public cult; she was honoured, above all, as the mother of Achilles and as one of the kindly powers of the sea, rather than through a great network of temples. As a Nereid she shared in the general reverence the Greeks felt for the daughters of Nereus — the gentle sea-nymphs to whom sailors and coastal peoples prayed for calm water and safe passage, and into whose element libations were poured. Where the sea gave life and took it, the Nereids and their chief were near.

Thetideion — her precinct in Thessaly

Her cult was rooted, naturally, in Thessaly, the land of Peleus and Achilles and the setting of her marriage. There stood a sanctuary called the Thetideion, a precinct of Thetis in the plain of Pharsalus, mentioned by later writers (it appears in Euripides' Andromache and in the historians as a landmark) — a shrine to the goddess in the very country over which her mortal husband had ruled and where her son was born. In this her worship was of a piece with the deep Thessalian and northern-Greek memory of Achilles and the house of Peleus.

Laconia and the sea-cult

Pausanias (Description of Greece 3.14.4) records a genuine and unusual cult of Thetis at Sparta: the Spartans, he says, possessed an ancient wooden image of Thetis kept with special secrecy and reverence, and there was a sanctuary of Thetis in Laconia whose founding-story he relates — a priestess-tradition and a xoanon (old carved image) passed down with great sanctity. This is the clearest evidence that Thetis received true cult, not merely poetic honour, in at least one corner of the Greek world. Beyond it, she belonged to the shared worship of the sea: fishermen and sailors along many coasts honoured the Nereids collectively, and Thetis, their chief, among them, with offerings cast upon the waves for the goodwill of the deep.

The mother in the poems

More than through altars, Thetis has always lived through Homer, and it is in the Iliad that the modern world meets her — one of the most moving portraits of motherhood in all of ancient literature. The silver-footed goddess rising from the grey sea to comfort her weeping son, going up to Olympus to plead for him though she knows it hastens his death, carrying him the god-forged armour with tears in her eyes, gathering her sisters to mourn a hero not yet fallen: these scenes have made Thetis the enduring image of the parent who loves a mortal child fated to die, and who cannot, for all her power, save him. Her grief is the human heart of the Iliad's divine machinery, and readers and poets have returned to it for nearly three thousand years.

A patron of mothers and the sea

In contemporary Hellenic devotion Thetis is honoured chiefly in two aspects. As a sea-goddess and chief of the Nereids she belongs with the gentle powers of the deep, and a devotee might pour a libation of wine or fresh water into the sea in her name, or offer a prayer for safe passage over water. And as the archetypal grieving mother, she is a fitting patron for those who carry fear or sorrow for their children: a candle lit, a few words of her story told, a small remembrance of the goddess who tried by fire and by every art to shield her son and who did not turn from him even into death. Her worship, like the ancient one, is quiet and personal, keyed to the love and the loss that her whole myth embodies.

The silver foot in the imagination

Thetis endures, too, in art and letters far beyond formal cult. The shape-shifting wrestling-match with Peleus was a favourite of Greek vase-painters, who loved to show the goddess turning to lion and serpent and flame in the hero's grip; the wedding of Peleus and Thetis and the apple of Eris stand at the head of the whole Trojan cycle and have been painted and retold endlessly; and the Shield of Achilles she commissioned is one of the most influential images in Western poetry, reworked by W. H. Auden in a famous modern poem that sets Thetis's hope for her son against the bleak world Hephaestus actually engraves. The name Thetis has been given to a moon-crater and to ships and to a great vanished sea of geologic time (the Tethys Ocean, named for her near-namesake). But her truest modern life is the oldest one: the silver-footed goddess of the Iliad, the immortal mother weeping on the shore for the mortal son she was fated to bear and to bury.