This plaquette is based on an important 1st-century gem attributed to Diskourides that passed into the Medici collection in the 1400s. The antique carnelian stone was so popular that the design was copied in numerous variations and media. In Ovid's Metamorphoses, Marsyas challenged Apollo to a music contest: his flute versus the god's lyre. As punishment for Marsyas's hubris, Apollo bound him to a tree and had his skin flayed. In the middle of the composition is the diminutive Olympus, Marsyas's student, begging Apollo for mercy. While the exact function of this plaquette is not clear, the subject had significance for political and noble figures in the Renaissance. The lyre symbolized peace, and thus the victory of Apollo's lyre stood for the triumph of universal harmony. When Pope Paul II Barbo (1417–1471) commissioned a portrait medal in 1468, the reverse included this same image, making the connection between his papacy and the new "Peace of Italy."