Crivelli compressed the story of Saint George—who saved a city and its princess from the marauding dragon—into a single, dynamic moment. Run through with a lance, the monster roars in agony, frightening this saint's steed. The horse rears up and shies away, eyes wide with fear.  In a feat of remarkable horsemanship, George stands, drops the reins and draws his sword to deliver the death blow. A rare subject for the side panel of an altarpiece, this image constituted the right side of the Porto San Giorgio polyptych.