Who is “she who slew the Gorgon” in Euripides?

Question

In Euripides' Ion, we find the following lines in a dialogue between Ion and his mother Creusa (Perseus Digital Library text in parallel with Coleridge's translation):

Κρέουσα: ἴστω Γοργοφόνα —
Creusa: Be witness she who slew the Gorgon,

Ἴων: τί τοῦτ᾽ ἔλεξας;
Ion: What meanest thou?

Κρέουσα: ἃ σκοπέλοις ἐπ᾽ ἐμοῖς / τὸν ἐλαιοφυῆ πάγον / θάσσει —
Creusa: She that on my native rocks makes the olive-clad hill her seat.

I'm with Ion: what (or who) does Creusa mean? Not Perseus, usually credited as the Gorgon's slayer, but wouldn't be called "she". Is it Athena, who bore the Gorgon's head on the Aegis, who's associated with olive trees, and who plays a significant role in Ion? (Or as an unlikely possibility, Perseus's daughter Gorgophone, whose name means "Gorgon-slayer"?)

Does this reference some version of the Gorgon myth in which Perseus wasn't the slayer? Perhaps even a version where the Gorgon wasn't identified with Medusa?

Answer 1

According to the 1911 Encyclopaedia Britannica, it seems that yes, it means Athena, and yes, it's a version of the "gorgon" myth distinct from Medusa and Perseus.

The Attic tradition, reproduced in Euripides (Ion 1002), regarded the Gorgon as a monster, produced by Gaea to aid her sons the giants against the gods and slain by Athena (the passage is a locus classicus on the aegis of Athena).

There are several sources cited, several not in English; I haven't yet puzzled out any specific source for this "Attic tradition", with the mention of Gaea and the giants, but the first citation (Harrison 1903) makes some interesting claims relevant to this question: namely, that the idea of a Gorgon, a detached head with a horrible face, predates any particular myth.