John VIII Paleologus, Emperor of Byzantium (b. 1392; r. 1425–48)
Arguably the first true portrait medal, this was made to commemorate the 1438 visit of the Byzantine emperor John VIII Paleologus to Italy to seek reconciliation between the Orthodox and the Roman churches and to enlist aid against the Turks. Pisanello, court artist of Leonello d'Este when the Greek delegation traveled to Italy, created the portrait of the Byzantine emperor inspired by, but not in imitation of, Roman imperial portraits on coins; the idea may have been suggested by Leon Battista Alberti, who was also in Ferrara at the time. The reverse represents the emperor interrupting one of his favorite activities (hunting) to pray at a cross, which alludes to the main purpose of his trip to Italy.
Source: Scher, Stephen K., et al. The Scher Collection of Commemorative Medals. New York and London, 2019.