In very ancient times there lived in Thessaly a king and queen name Athamas and Nephele. They had two children, a boy and a girl. After a time Athamas grew indifferent to his wife, put her away, and took another. Nephele suspected danger to her children from the influence of the step-mother, and took measures to send them out of her reach. Mercury assisted her, and gave her a ram with a golden fleece, on which she set the two children, trusting that the ram would convey them to a place of safety. The ram vaulted into the air with the children on his back, taking his course to the East, till when crossing the strait that divides Europe and Asia, the girl, whose name was Helle, fell from his back into the sea, which from her was called the Hellespont—now the Dardanelles. The ram continued his career till he reached the kingdom of Colchis, on the eastern shore of the Black Sea, where he safely landed the boy Phryxus, who was hospitably received by AEetes, king of the country. Phryxus sacrificed the ram to Jupiter, and gave the Golden Fleece to AEetes, who placed it in a consecrated rove, under the care of a sleepless dragon.
There was another kingdom in Thessaly near to that of Athamas, and ruled over by a relative of his. The king AEson, being tired of the cares of government, surrendered his crown to his brother Pelias on condition that he should hold it only during the minority of Jason, the son of AEson. When Jason was grown up and came to demand the crown from his uncle, Pelias pretended to be willing to yield it, but at the same time suggested to the young man the glorious adventure of going in quest of the Golden Fleece, which it was well known was in the kingdom of Colchis, and was, as Pelias pretended, the rightful property of their family. Jason was pleased with the thought and forthwith made preparations for the expedition.