What was the Sphinx in Greek mythology?

The Sphinx

The Sphinx is the riddling, man-eating creature of Greek myth that Hesiod calls Phix and sets loose on Thebes, with a woman's face, a lion's body and wings. She questions everyone who approaches the city and kills those who cannot answer, until Oedipus solves the riddle — a riddle none of the surviving early sources actually write down. The ancient writers do not agree on her parentage either, or on what became of her once it was answered.

The facts

Parents: Typhon and Echidna
Also known as: Phix

In short

Hesiod's Theogony (326-329) is the earliest source for the Sphinx, but the Greek is genuinely ambiguous about whether her mother is Echidna or the Chimaera, and Apollodorus later names Typhon, not Orthus, as her father.
Hesiod calls her Phix, the Boeotian form of her name, and the Boeotian mountain Phicium carries the same word.
Neither Hesiod's Theogony nor Homer's Odyssey, which tells of Oedipus and his mother Epicaste directly, mentions the Sphinx at all; Sophocles calls her only "the riddling Sphinx" (Oedipus Tyrannus 130-131) without repeating what she asked.
The earliest source to give the riddle's actual wording is Athenaeus, writing around AD 200, who credits it to a lost fourth-century BC study of tragedy by Asclepiades of Tragilus.
Aelian pairs Egyptian sculpture with Theban legend as two attempts at one 'twofold nature'; Pliny's Sphinx of Giza is a different creature again — a monument revered as a divinity and tied to a king's burial, approached in silence rather than with a riddle.
Apollodorus and Diodorus both have her throw herself from a height once Oedipus answers correctly; Pausanias instead records two rationalised Boeotian accounts, a defeated pirate war-band and a loyalty test run by Laius's illegitimate daughter, in which she is never a monster at all.

The answer that releases Thebes

Oedipus approaches Thebes after the Sphinx has killed those who cannot answer her. He identifies the creature that walks on four legs in the morning, two at noon and three in the evening as a human being, crawling in infancy and using a staff in old age. The answer ends the blockade and brings him the vacant throne.

None of the earliest surviving sources gives that wording. Hesiod says only that the creature destroyed the Cadmeans. Homer tells of Oedipus without mentioning her, and Sophocles calls her the riddling Sphinx without repeating the question. Athenaeus, writing around AD 200, preserves the first surviving text of the riddle and attributes it to a lost fourth-century BC work by Asclepiades of Tragilus. The famous words arrive centuries after the creature and the solver.

Phix and the parents no source settles

Hesiod calls her Phix, the Boeotian form also attached to Mount Phicium. His compact genealogy can be read with Echidna or the Chimaera as her mother while Orthus remains the father. Apollodorus changes the pairing altogether, naming Echidna and Typhon. The fact panel follows that later dominant account; the body preserves the earlier ambiguity rather than pretending all three names belong to one settled family.

Not Egypt’s creature

Aelian sets the two side by side on purpose. “The Egyptians who work in sculpture, and the boastful legends of Thebes,” he writes, both reach for a “twofold nature” and “try to show us a double-formed creature,” built “from the body of a maiden and of a lion”; his own gloss makes plain that sculptors and mythographers solve the same problem differently. Pliny’s Sphinx, the Great Sphinx at Giza, is a different being doing a different job: “a still more wondrous object of art, but one upon which silence has been observed, as it is looked upon as a divinity,” which the people living nearby believed held the burial of “King Harmaïs.” No riddle and no traveller stopped and questioned. This stone was approached with silence and tied to a king rather than to a maiden’s face.

What the sources cannot agree happened next

Apollodorus and Diodorus agree on the ending, if nothing else that came before it: once Oedipus gives the answer, “the Sphinx threw herself from the citadel,” Diodorus adding that she did it “in accordance with the oracle which the myth recounts.” Pausanias, describing the Boeotian mountain where locals placed her, gives two entirely different stories, and neither one ends that way. In one, she is no monster at all but a raiding leader who “put in at Anthedon” with a force of ships and seized the mountain “until Oedipus overwhelmed her by the superior numbers of the army” he brought from Corinth. In the other, she is Laius’s illegitimate daughter, entrusted with a secret oracle and using it to bar her half-brothers from a throne that should have gone to Epicaste’s sons. Both of Pausanias’s Sphinxes die by defeat or exposure, not by a leap answering a riddle. On the ground where the story is set, the fixed mythographic ending is one telling among three.

A different sphinx, raised in marble at Delphi

The Naxians did not carve a warning. Around 560 BC they raised a marble sphinx on a column of six drums topped with an Ionic capital, one of the earliest such capitals standing, beside the sanctuary of Apollo at Delphi. Three large fragments of the body came up from beneath the sanctuary’s polygonal retaining wall in 1861; the statue itself stands 2.22 metres, the whole monument, column and base included, near 12.45. It was a gift, not a guardian set against travellers: the Naxians dedicated it to Pythian Apollo for promanteia, the privilege of putting a question to the oracle ahead of other petitioners waiting their turn, and a fourth-century BC inscription on the base renewed the same privilege generations later. The winged, woman-headed type does two kinds of work. It demands death from strangers in the Theban myth and asks nothing in the sanctuary. The second still stands in the Delphi Archaeological Museum.

Where to stand

Delphi

Cultural Sites

The Naxians raised this marble sphinx on an Ionic column beside the sanctuary of Apollo at Delphi around 560 BC — not the monster of the Theban story, but the same winged, woman-headed guardian type in stone, over 12 metres tall with its column and base. The base carries a fourth-century BC inscription renewing the Naxians' promanteia, the right to put a question to the oracle ahead of other visitors, and the statue now stands in the Delphi Archaeological Museum.
Delphi

Family

Typhon Father
Echidna Mother