Argonautica only defended by birds. They fight off the birds and then chance upon four survivors of a shipwreck. These are the four sons of the exiled Greek hero, Phrixus, and they are also grandsons of Aetes, king of Colchis. Jason welcomes them as god-sent allies in his quest for the Golden Fleece. Approaching Colchis, the Argonauts see the eagle of Zeus flying to and from the Caucasus mountains, where it feeds on the liver of Prometheus. It glides through the air as large as another ship, disturbing the Argo's sails as it passes overhead. Soon after, the heroes enter the
Golden Fleece the Golden Fleece signified the bringing of sheep husbandry to Greece from the east; in other readings, scholars theorized it referred to golden grain, or to the sun. A more widespread interpretation relates the myth of the fleece to a method of washing gold from streams, which was well attested (but only from c. 5th century BC) in the region of Georgia to the east of the Black Sea. Sheep fleeces, sometimes stretched over a wood frame, would be submerged in the stream, and gold flecks borne down from upstream placer deposits would collect in them. The fleeces would be