JASON, JASOUN. Jason, son of Aeson, successfully brought the Golden Fleece of the Ram of Phrixus from Colchis to Thessaly. The story of the expedition was one of the favorites from late antiquity through the medieval period. Guido de Columnis, Historia destructionis Troiae, devotes Books I-III to the adventures of Jason and his men. Dante places Jason among the seducers, in Circle VIII of Hell, Inf XVIII.86-87. Jason appears in the blazon des faulse amours, RR 13173-13280. Machaut mentions his betrayal of Medea, Le jugement dou roy de Navarre, 2770-2804; in Confessio Amantis V.3247-4257 the Confessor tells the story of Jason and Medea to illustrate the sin of perjury among lovers, citing Ovid as a source (Met VII.1-403; OM VII.250-1506).

Jason is a false lover every time he is named, MLI 74; SqT 549-551; BD 330-334, 724-727; HF I.395-400; LGW F 266; LGW G 220. Jason is the "rote of false lovers," LGW 1368-1377, 1389-1393. He is extraordinarily beautiful, LGW 1548-1608, but a devourer of love, LGW 1580-1583, a bottomless well, LGW 1584-1585. Chaucer seems to have had a particular dislike for Jason. Most villains are false to one woman, but he is false to two. The narrator of the "Legend of Hypsiphile and Medea" challenges him to a duel: "Have at thee, Jasoun," LGW 1383. Jason swears to be true to Medea before the gods, but he is chief traitor in love, LGW 1629-1659. [Ercules: Eson: Isiphile: Medea: Pelleus]

Jason occurs five times initially, SqT 549; LGW 1451, 1589, 1611; thirty-one times in medial positions, MLI 74, SqT 548; HF I.400, 401; LGW 1383, 1394, 1402, 1410, 1415, 1419, 1440, 1454, 1472, 1480, 1499, 1501, 1513, 1524, 1544, 1548, 1559, 1570, 1576, 1585, 1601, 1603, 1620, 1636, 1651, 1654, 1667; and once in final rhyming position, BD 330; Jasoun occurs seven times, in final rhyming position only, BD 727; LGW F 266, LGW G 220; LGW 1368, 1420, 1580, 1663.