Why is Jean Mabillon considered a founder of diplomatics?

Jean Mabillon is considered the founder of diplomatics because he established the systematic principles for evaluating the authenticity and dating of medieval manuscripts in his seminal work, De Re Diplomatica (1681).1

By developing these critical methods, Mabillon effectively created the science of diplomatics—the formal study of historical sources—and pioneered paleography, the study of ancient handwriting, which is fundamental to the field. His work was prompted by a scholarly controversy with the Jesuit Daniel Papebroch, who had claimed that most Merovingian documents were forgeries. Mabillon’s rigorous, evidence-based approach successfully challenged these assertions and provided a scholarly framework that remains the foundation for the critical analysis of historical documents.1