Barbarians by Profession: Ethnically Defined Law and Collision Rules in the Early Medieval West

Compared to the Later Roman Empire, the legal culture of the early medieval West witnessed a far-reaching diversification of ethnically defined law, most visible through the co-existence of several written "leges barbarorum’." Such plurality of law called for the development of "collision rules" in order to determine which law would be applied to what person and in which legal matter, such as the so-called "principle of personality of law" or the professio iuris. While most of these regulations appear to have been first introduced by the Frankish rulers of the Merovingian and Carolingian age, it becomes clearer, on closer inspection, that some of the most important means and devices to cope with an ethnically defined legal pluralism had actually been adopted from late Roman military law and provincial organization. This paper seeks to trace this feature back to its late Roman roots and discusses the relevance and consequences of its adaptation and further development by the Franks.