Daughter of King Athamas and Nephele and after whom the Dardanelles is classically called Hellespont or the sea of Helle.
She and her brother, Phrixos, rode on the back of the winged Chrysomallus - Hermes' golden fleeced Ram escaping Phrixos’ sacrifice at the altar of Zeus. A sacrifice staged by their wicked step-mother after having bribed messengers to the oracle of Delphi seeking answers to a famine that she instigated. Nephele, who had sent Chrysomallus to save them, filled the place with a thick cloud allowing them to escape.
They flew quite a distance safely until in the vicinity of Sigeion and Thrace Helle, leaning too far, slipped and fell into the strait (the Dardanelles) below.