Which law applies in cross-border cases is a question that medieval and early modern jurists alike have tried to answer in their theories of statuta . Kristin Boosfeld's study traces how the theories changed over time and identifies reasons for the change in the concept of law at each specific time and place.

Which law applies in cross-border cases? Medieval and early modern jurists tried to solve conflicts of laws through their theories of statuta. The book examines how these theories evolved over time and identifies reasons for changes in the concept of 'law' at specific times in specific places it thereby presents the late medieval and early modern so-called conflict of laws theory in a new light. This theory has its roots in the writings of northern Italian jurists of the 13th and 14th centuries who worked on the applicability of their respective city laws (statuta). Especially the writings of Bartolus de Saxoferrato (13131357) and his student Baldus de Ubaldis (13271400) were read and widely cited in Europe as of the 16th century. However, they were not merely adopted, but also adapted to the local situation. The book examines to what extent the later theories must be understood against the background of the state structures existing at a specific time and a specific place.
The book begins with an analysis of the late medieval theories of Bartolus and Baldus. Both developed universal theories determining the scope of application of statutes and customary laws alike. Depending on the legal question involved, local satutes and customs could extend to subjects outside the territory or to foreigners inside the territory. Bartolus and Baldus paint a picture of scholastic distinctions and overlapping arguments for and against the applicability of statutes and customs against the backdrop of the Roman-Canonist ius commune (§ 1).
Bertrand d'Argentré (Argentraeus), who lived in Brittany between 1519 and 1590, left these complicated scholastic distinctions behind. His writings instead focused on the territory and aimed as far as possible at the application of local law within the territory. Therefore, he argued that only rules specifically concerning a person as such (statuta personalia) should be applied outside the territory. Reasons for this strong territoriality can be found in his biography, for d'Argentré was a local patriot whose aim it was to strengthen Breton law against French centralising tendencies. By contrast, the conflicts writings of his contemporary Charles Dumoulin (Molinaeus 15001566) are more closely connected with late medieval ideas, since Dumoulin who came from Paris and was a supporter of the monarchy, was in favour of unifying French law on the basis of the Coutume de Paris (§ 2).
During the 17th century, a new theory of statuta developed in the provinces of the United Netherlands. This so-called 'doctrine of comity' still referred to the older theories, but focused on a new argument. The reason lies in the historical situation of the Dutch provinces, which had been successful in their efforts to secure sovereignty in the Peace Treaty of Westphalia in 1648. In light of their recently acquired sovereignty, Dutch jurists were looking for an explanation why foreign law should be applicable within the territory at all. Jurists like Paulus Voet (16191667), Ulrik Huber (16361694) and Johannes Voet (16471713) found this explanation in the idea of comity, the friendly, mutual courtesy of peoples. According to the principle of sovereignty, no state could be under a duty to apply foreign law. However, since the application of foreign law was necessary to avoid impairments to trade (the economic boom in the Netherlands in the 17th century was primarily based on trade by ambitious Dutch businessmen), they argued that 'foreign' law should be applied out of courtesy (§ 3).
German jurists of the 17th century rejected d'Argentré's writings and the entire Dutch doctrine of comity. The great number of citations shows that their writings are again closely connected with the writings of late medieval Italian lawyers. This must be understood against the background that German jurists were at the time confronted with a plurality of laws which had structural similarities with the late medieval situation. By contrast with the Dutch provinces, the territorial states in early modern Germany remained part of the Holy Roman Empire. Even though the Emperor only exercised power in limited fields of law, this influenced German jurists' understanding of private international law, since they were confronted with a complex interplay of local laws and the ius commune. This did not leave space for a doctrine of comity because the latter presupposed sovereign states with concurring legal systems. It did not provide answers, however, for the complex interplay of laws during the German Usus modernus (§ 4).
It is remarkable that all conflicts theories examined in the book are formulated as universal doctrines. Even though they have individual characteristics because they were formulated in a specific legal situation, they were not formulated as national theories and thus they claimed for themselves universal applicability Differently to modern conflict of laws rules, which must in principle be understood as (partly Europeanised) national rules, private international law was not understood as national law well into the 19th century. This undermines the argument of contemporary critics of the theories of statuta, who maintain that unilateral conflicts norms often lead to contradictory results, for a conflicts theory of universally thought unilateral conflicts rules comes close to a national set of multilateral conflicts rules.
A source book with transcriptions and German translations of the central texts of conflicts of laws between the 14th and 17th centuries is currently in the process of being compiled.

Autorentext
is Professor of Civil Law and Related Areas, Foreign and European Private Law, and Director of the Institute for Foreign and International Private Law, Section I, at the University of Freiburg.

Inhalt
Einführung
§ 1 Oberitalien, 14. Jahrhundert - Konsolidierung einer Lehre: Bartolus und Baldus
§ 2 Nordfrankreich, 16. Jahrhundert - Alt gegen neu? Der Streit zwischen Dumoulin und d'Argentré
§ 3 Niederlande, 17. Jahrhundert - Staatshoheit und comitas : P. Voet, U. Huber und J. Voet
§ 4 Deutschland, 17. Jahrhundert - Statutenlehre und Territorialgewalt: Hert und Stryk
Schluss