1 [Mandatory rules in international business transactions] Abstract Nowadays, international elements often penetrate legal relations, which may interfere with the fundamental values of individual states. The mandatory rules of private international law offer protection against such unwanted interferences. These rules represent social, political and economic organization of the state and they apply always regardless of the applicable law of the legal relationship. Although the purpose of mandatory rules is obvious, there are many questions about their application in practice. This thesis offers an overview of possible answers concerning the definition, naming of this type of rules or determination of their mandatory character. Furthermore, the work categorizes mandatory rules according to their function and origin and explains the difference between mandatory rules in the context of private international law and national law. The thesis describes issues of mandatory rules that protect weaker parties of obligations and their international mandatory character. Example of contradictory opinions is based on case-law of the Court of Justice of the European Union in cases Ingmar and Unamar, which recognizes international mandatory character of these rules, and on German doctrine and case-law, which considers these...

L’autonomie de la volonté est un principe relatif à la liberté des parties quant au choix de la loi applicable au contrat international. Cependant, ce principe est limité par les règles d’ordre public, et plus généralement les dispositions impératives, réduisant l’étendue de cette autonomie. Afin de perfectionner la mise en application de ces règles tout en garantissant une certaine prévisibilité, il s’avère important d’étudier en détail l’origine et la nature des règles d’ordre public. Une étude comparée avec le droit international privé égyptien s’avère nécessaire pour perfectionner les mécanismes actuels. Le débat conceptuel actuel met en évidence le rôle de la coopération internationale, outre les intérêts purement étatiques, ce qui suscitera un nouvel ordre public transnational, voire supranational. / The freedom of choice is a principle referring to the freedom of the parties concerning the choice of the law ruling the international contract. However, this principle is limited by public policy, which reduce the extent of this freedom. In order to improve the application of these rules with a minimum of predictability, it is important to study in detail the origin and nature of the rules of public policy. A comparative study with Egyptian private international law is needed to take advantage from all current mechanisms. The current conceptual debate highlights the role of international cooperation, in addition to purely State interests, which will tend to create a new transnational, or even supranational, public policy.