In Greek mythology, Phrixus (Ancient Greek: Φρίξος) was the son of Athamas of Boeotia and the cloud-nymph Nephele, older brother of Helle. Rescued from a stepmother's sacrificial plot by a golden-fleeced ram, he alone reached Colchis, sacrificed the ram, and gave its fleece to King Aeëtes — the prize that later drew Jason and the Argonauts. He married Chalciope and fathered Argus, Phrontis, Melas, and Cytisorus.
Adapted from Wikipedia, "Phrixus" · CC BY-SA 4.0
I.Flight from Boeotia
Phrixus and Helle were hated by their stepmother Ino. She roasted Boeotia's crop seeds so they would not grow; when farmers consulted an oracle, she bribed the messengers to report that the dearth required the sacrifice of Phrixus (and in some tellings Helle). Before the killing, Nephele sent a flying — or swimming — ram with golden wool. Their starting point is variously Halos in Thessaly or Orchomenus in Boeotia.
During the flight Helle fell into the strait between Europe and Asia, thereafter called the Hellespont ("sea of Helle"). Phrixus reached Colchis alone.
II.Colchis and the Fleece
King Aeëtes, son of Helios, received him kindly and gave him his daughter Chalciope in marriage. In gratitude Phrixus sacrificed the ram to Zeus (or, less commonly, Poseidon) and gave Aeëtes the Golden Fleece, which the king hung in a tree in the holy grove of Ares, guarded by a sleepless dragon. Phrixus and Chalciope had four sons — Argus, Phrontis, Melas, and Cytisorus — who later joined forces with the Argonauts.
Some sources say Phrixus lived peacefully and died of old age at Aeëtes's court; others claim Aeëtes, warned by an oracle that he would die by a descendant of Aeolus, killed him.