Peleus was a powerful king who also was very worthy, sage and courtly. His dominion extended across Greece and he ruled a very large part of the realm. He held his land freely, in great peace and wisely. This king had a brother, son of the same father and mother, who was called Aeson. I do not know whether he was king, count or duke of the city of Peloponnesus, for Dares's Book does not tell me anything more about him. This Aeson had a son named Jason, who, as I find it, was very handsome, worthy and intelligent. He was very strong and powerful, and known throughout many a realm. Being very courtly, noble and honourable, he was greatly loved by all. He conducted himself in a very noble fashion and was very fond of fame and largesse. He was very highly regarded and had achieved so much since his youth that his name was widely known throughout many lands and regions. (715–40)

When King Peleus saw Jason's ever-increasing rise and his celebrity that grew daily, he became anxious and began to fear that his nephew might grow and rise so high that he would drive him out of his own land. He was afraid that, if Jason lived long, he would leave nothing to his uncle. Peleus profoundly feared being ousted from his kingdom, for if Jason should decide to attempt this he could easily drive him away completely. Peleus harboured very treacherous feelings towards Jason. All he could think of was how he might plot and contrive to destroy his nephew, so as to keep his lands from him and prevent him from doing him any harm. Peleus made every effort to deceive Jason, although he kept his thoughts very much to himself, showing his nephew no sign of his intentions. During this time, as I find in my reading, a great marvel appeared on the island of Colcos in the sea; that is how I heard the place named not long ago. As is well known, there was a sheep there with a fleece all of gold.