This article studies portraits painted on panel of the bust of Philip the Good, Duke of Burgundy. The in-depth analysis of a virtually unknown effigy, from the old Hôpital de la Madeleine in Ath, now kept in the local Musée d'Histoire et Folklore, sheds a new light on the rest of the corpus. Along with a brief summary of the research on the portraits of the duke, a detailed comparison is made between these and the panel from Ath, which turned out to be a real unicum inciting unpublished observations. This article aims to define all the iconographic, stylistic and contextual criteria allowing a better understanding of the painting. Its recent restoration by the Royal Institute for Cultural Heritage (KIK-IRPA) made available technical data that are used as a starting point for a series of assumptions on dating, attribution, function and material history.Prix - Prijs Simone Bergmans, 2014