V. Prott, Lyndel Keywords: Monuments of architecture, art or history | Cultural heritage | Private international law | Mots clefs: Monuments d’architecture, d art ou historiques | ABSTRACT There is a need for unity in private international law and a need for rules that can be of general application and justified by a reason. Such a need is particularly felt with regard to problems of cultural heritage protection. The complexity and diversity of the rules allow illegal trade participants in the cultural heritage to take adv…