An allegory is a picture in which meaning is symbolically represented. van Loon would use allegory as a way to represent events and concepts. For instance, van Loon chose to depict the Inquisition as a jail door, Napoleon as a specter haunting Europe, and the handful of diplomats of the Congress of Vienna redrawing the boundaries of Europe, the emptiness of the room in which they work showing how anti-democracy the Congress was. Perhaps van Loon’s use of allegory explains the reviewer’s comment that van Loon’s drawings required a mature understanding of the symbolism.