Conceptual Interrelationships of Lex Mercatoria and Transnational Commercial Law

With  the growth of transactional commercial arbitrations in the 20th century, the theory of ‘Transactional Commercial Law’ was proposed by jurists such as Goldman and Schmitthoff, according to which, there is a third legal system along with the system of international law and national law which adjusts transnational commercial relations. There is no consensus among legal scholars about the concept, nature and other issues surrounding transnational commercial law and its study invites ambiguities. Considering the history of transnational commercial rules, some scholars consider this new legal system equivalent to traditional and customary trade law of medieval merchants (Lex Mercatoria), whereas Lex Mercatoria has never had a fixed concept and its meaning has developed over time. Based on a library study and a descriptive-analytical approach, this article studies and assesses the evolutionary process of Lex Mercatoria and clarifies its interrelationships with Transnational Commercial Law. Finally, it is concluded that the comprehensive definition for Lex Mercatoria is not equivalent of Transnational Commercial Law (including in its broad or restrictive sense) without specifying certain characteristic such as classical, modern, and post-modern in which the post-modern Lex Mercatoria comes closer to the concept of Transnational Commercial Law in its restrictive sense.