Where does “Екатери́на” come from?

Екатери́на (Russian) comes from Ancient Greek Αἰκατερίνη, from Ancient Greek Ἑκάτη, from Ancient Greek ἑκάς, from Ancient Greek ἕ, from Proto-Hellenic hwe, from Proto-Indo-European swé — self.

Екатери́на (Russian): Catherine; {{w|Catherine the Great}}; Katherine