According to legend, Jason was the son of Eson, King of Iolcos in Thessaly. To regain his throne, usurped by his uncle Pelias, he embarked on a perilous quest, accompanied by his companions, the Argonauts. The story is best known through the epic by Apollonius of Rhodes, entitled "The Argonautics".
The group's main objective was to find and bring back the Golden Fleece, the skin of a mythical ram with magical powers, which was to be found in a faraway land called Colchis, where the hero seduced the princess Medea, renowned for her magical gifts. She helped him seize the fleece, which was being guarded by a dangerous dragon, by preparing a poison to put it to sleep. Jason finished off the beast before fleeing with the fleece, accompanied by the princess.
The battle scene takes place in the centre of a cave. Jason, dressed in gleaming armour, steps over the fearsome dragon while pouring poisonous juices into its gaping maw with his left hand.
Engravings depicting this same episode were made after Rosa, among others by an 18th-century engraver named Raphael Lamar West.
Provenance: Lord Blythswood collection, label on the back of the stretcher.