Sources contemporaneous with Sophocles list the Sphinx’s parents as Typhon and Echidna, two primordial monsters known for their terrifying, bloodthirsty children. She is not a blood-relation of the Olympian gods and her Otherness is a distinct entity from theirs; she is older, darker, and more chaotic. Her brothers and sisters include the Chimera, Cerberus, the Hydra, the Nemean Lion and at least fifteen other monsters of legend. For the purposes of Sophocles, the Sphinx is an individual being rather than a species (multiple sphinxes will be seen on art of the period, but for our purposes we will adhere to the singular Sphinx). She is originally an Egyptian creature, though Egyptian sphinxes are more commonly depicted with male heads.
Physical descriptions of the Sphinx are consistent across periods (lion-bodied, eagle-winged, woman-headed, with a snake-tail added in for flavor in some iterations), but her motivations for terrorizing Thebes wildly vary. Sometimes she is Hera-sent, a punishment for Laius abducting a young girl, sometimes sent by Ares as vengeance against the line of Cadmus. The serpent Cadmus slew to found the city of Thebes had been sacred to him, once upon a time, and the memory and wrath of a god are equally long. Other culprits include Hades or Dionysus, but none of these versions is exactly contemporaneous with Sophocles, nor are any of these motivations textually supported.
From the text of Oedipus Rex, we know only that she had planted herself in Thebes, refusing to leave unless her riddle is answered. We know that she killed the inhabitants of the city, perhaps in the form of demanding human tribute or perhaps devouring those who failed to answer her riddle. Creon points to the Sphinx’s occupation of Thebes as the reason why the investigation into Laius’ murder stopped dead in its tracks and the Sphinx herself is the reason Laius made his fateful (and aborted) journey to Delphi and met his son upon the road. Oedipus himself is, as attested by his own timeline, in the process of fleeing Corinth upon learning of his prophesied fate. After killing Laius on the road, he arrives in Thebes and finds the city in the monster’s clutches. He answers her riddle and, by most accounts, she flings herself from the cliff on which she is perched. Whether or not this means her death is unclear, but she is never seen again in Thebes. Oedipus is hailed as savior of Thebes, crowned, married, and Thebes sees a period of peace and prosperity before the play-heralding plague rises up to consume them.
A chief and perhaps unexpected feature of the Theban Sphinx is her connection to song, particularly religious song. Many of the words used to describe her riddles have musical or chant-adjacent connotations. She is a bard of sorts, a weaver of music and cryptic words, as well as a man-eating monster, a creature of darkness born from the earth, defeated not by physical strength but by cleverness and words.
In Oedipus at Colonus, we find an echo of the Sphinx in the Furies; winged female primordial entities, older and more bloodthirsty than the Olympian gods, with heavy ties to song. Sound familiar?
The Furies (Erinyes) are bringers of retribution and exacters of vengeance, particularly against those who wrong their kin. Their most famous turn on the Athenian stage comes in Aeschylus’ Eumenides (named for their epithet “The Kindly Ones”, often spoken in appeasement or fear), where they hound Orestes across the land for killing his mother Clytemnestra. They represent a non-democratic form of justice, the natural law that arises from divinity and divinity alone, blood for blood, an eye for an eye. This vengeance manifests through madness, sickness, or simply death, most famously portrayed (again in Eumenides) through the chanting of a binding-curse over Orestes.
The parentage of the Furies is variable, but the most frequent listed progenitors are: Nyx, the personification of night; Gaia (Earth) and the blood of the castrated Ouranos (Sky); the union of Hades and Persephone. Descriptions are variable as well, but some features stick out. The Erinyes are always female, always winged, and somehow clad in or attended by serpents. Their faces are described as ugly, horrifying, and fierce, unsurprising for what their job description is. Of all the deities, this is not the one whose sacred grove one would want to disturb, especially not as a kinslayer. The anxiety of Colonus’ Chorus is well-placed when they attempt to cast Oedipus out of the grove; the Furies are not known for being forgiving.
It is for this very reason that Oedipus’ entrance into (and divinely-aided exit from) the Grove of the Eumenides is so startling, both to a modern audience and to the Athenian one watching the world premiere. Oedipus has committed patridice, violated his mother, a man who has wronged his own family twice over in ways that the Furies are very nearly obligated to avenge---
And they do not. Oedipus greets them with reverence and, later on in the text, even a sort of gentle familiarity. He makes himself at home in their most sacred place and is not cast forth, is driven neither to madness nor to illness, and his death is peaceful.
-Emma