International audienceIn his various works on Frankish Greece, Du Cange grants a singular function to heraldry, considering it as a full-fledged auxiliary science to enrich his historical narratives through various sources such as armorials, seals, and sculptures. Coats of arms allow him to trace genealogical links and identify noble families; Du Cange also employs heraldry to determine the origins of lineages based on research in ancient records and heraldic treatises. Coats of arms play a crucial role in political and social history, deciphering noble alliances and armorial concessions. Du Cange positions himself as a mediator between heraldists and historians, understanding their value as historical sources.Dans ses différents travaux su...