Phlegyas, son of Ares and Chryse, King of the Lapiths in Greek mythology was father of Ixion and Coronis, one of Apollo's lovers. Pregnant with Asclepius, Coronis fell in love with Ischys, son of Elatus. A crow informed Apollo of the affair and he sent his sister, Artemis, to kill Coronis. Apollo rescued the baby though and gave it to the centaurChiron to raise. Phlegyas was irate and torched the Apollonian temple at Delphi and Apollo killed him.
In Book VI of Virgil's Aeneid, Phlegyas is said to have imposed a powerful tyrant upon the Lapiths, changed laws when given bribes, and to have raped Coronis himself, despite his anger at Apollo for having done so.
Phlegyas was condemned to act as ferryman for the souls that cross the Styx, one of the four rivers of Hades. In the Dante Alighieri's Divine Comedy, Phlegias helps Virgil and Dante to cross that river.
Phlegyas was the mythical ancestor of the Phlegyans.
Styx is guarded by Phlegyas, who passes the souls from one side to another of the river.
The ferryman Charon is in modern times commonly believed to have transported the souls of the newly dead across this river into the underworld, though in the original Greek and Roman sources, as well as in Dante, it was the river Acheron that Charon plied.
Dante put Phlegyas over the Styx and made it the fifth circle of Hell, where the wrathful and sullen are punished by being perpetually drowned in the muddy waters.