Styx is presented in classical genealogies as a daughter of the primordial generation. In the standard Hesiodic account she is the offspring of Oceanus and Tethys (making her an Oceanid/river-nymph); a variant tradition (attested in classical summaries attributed to later mythographers such as Hyginus) names Nyx (Night) and Erebus (Darkness) as parents. During the Titanomachy Styx allied herself with Zeus and brought her children to his side; as a reward she and her offspring were granted honor and residence with Zeus and her waters became the binding medium for the gods' most solemn oaths.
Classical sources depict Styx as an imposing subterranean watercourse at or circling the entrance to Hades. Hesiod locates her 'at the entrance to Hades, in a cave propped up to heaven all round with silver pillars' with 'famous cold water' trickling from a high, beetling rock; Homer uses imagery of 'sheer-falling waters' and calls her the 'dread river of oath'; Virgil (later Roman epic tradition) describes a winding river that circles the underworld (notably nine times in his account). The shared imagery emphasizes cold, dread-inspiring, falling waters that mark the boundary of the otherworld.
Styx's primary power in the sources is ritual-ontological: her water is the authoritative medium by which the gods swear the most dreadful and inviolable oaths. Hesiod (Theogony) gives a procedural and punitive mechanism for oath-breaking: a god who swears by Styx and then breaks the oath is stricken—rendered breathless and barred from ambrosia/nectar for a full year, and then excluded from the gods' assemblies for nine additional years before restoration in the tenth year. Styx also functions as an underworld boundary (attested in Homer and Virgil) and possesses agency as a divine person who chose sides in the Titanomachy and whose offspring (Zelus, Nike, Kratos, and Bia) were granted place with Zeus. Iris is linked functionally as the messenger who fetches Styx's water when oaths are sworn.

Oceanus
Oceanus (Greek: Ὠκεανός) is a primordial Titan in ancient Greek cosmology who personifies the great river that encircles the world and is named as father of the river gods (potamoi) and the Oceanids. He functions as a cosmological boundary-stream and genealogical progenitor in multiple Greek traditions and appears in literary theogonies and Greco-Roman art.

Tethys
Tethys is attested in the provided materials primarily as a Titaness of Greek mythic tradition who in a modern children's retelling is presented as an elderly storyteller and mediator among gods. The name is also widely reused in scientific and cultural contexts (a Saturnian moon, a gastropod genus, the ancient Tethys Ocean, and various institutions), usages which are naming transfers rather than continuations of the mythic figure.

Charon
Charon (Χάρων) is the ferryman of the Greek underworld who conveys the souls of the dead across the boundary river (variously Acheron or Styx). He functions as an underworld attendant and psychopomp whose service typically requires funeral rites and payment (Charon's obol).
Community Record
- [1]Styx — Wikipedia (summary of classical sources). Wikipedia: 'Styx' article summarizing Hesiod, Homer, Virgil and related classical materialwiki
- [2]Wikidata: Styx. Wikidata entry for Styx (cross-references classical source identifiers)wiki
