Legitimisation of Historical Artifact Forgeries: Analytical Framework and Cases in Medieval Polish–Lithuanian Numismatics

This article investigates the phenomenon of numismatic forgery legitimisation and its impact on the fields of numismatics, archaeology, history and law. Forgery legitimisation is a broad phenomenon that encompasses both physical forgery and the presentation of fake artifacts as genuine in research literature, auction catalogues, and other contexts. Using the qualitative case-study methodology, the authors propose an analytical framework for suspected forgery legitimisation that incorporates a novel classification of forms and types of forgery, as well as socio-legal mens rea elements. The framework also accounts for factors contributing to the legitimisation of forgeries, including lack of competence, low competition in coin catalogue publication, tradition, closed numismatic communities, and insufficient academic and legal attention. Using this framework, the authors examine two cases of legitimisation of fake coins in medieval Polish–Lithuanian numismatics. The analysis shows how repetition across sources can legitimise fake artifacts, complicating later correction and corrupting heritage research, history and museum science, as well as market integrity. The proposed analytical framework can be useful for investigating other dubious artifacts and for developing analysis methods for forgery legitimisation cases.