The hero son of king Athamas of Boeotia, and grandson of king Aeolus. His mother was Nefele, the cloud, who was of divine nature. He also had a sister called Helle.
King Athamas took a new wife, Cadmus daughter Ino. She was a wicked stepmother and wanted to get rid of the children. Through her dark powers she caused he crops to fail in the country, and then forged a Delphic reply, making it say that Phrixos must be sacrificed in order to make things grow again.
Phrixos was just about to be killed, when his mother Nefele sent a ram with golden wool that took both children on its back and flew off. Helle didn't hold on tightly enough, and fell off the ram and drowned at what was to be called the Hellespont (Dardanelles).
Phrixos made it safely to Caucasus, where Aietes, he son of Helios, gave him his daughter to marry. They had many sons, some of which took part in the expedition of the Argonauts. The ram was sacrificed to Zeus as a thank offering, and its golden fleece was hung in the holy meadow of Ares in Colchis. The ram was later to become the star constellation Aries.