Jewish communities during the Middle Ages adhered to their local. This was also apparent in their legal institutions, so that internal juridical and ritual matters were commonly discussed by local rabbinical authorities or lay leaders. More controversial and complicated issues were addressed to Talmudic scholars of the same district or Diaspora (Sephardi, Ashkenazi, Italian, North African, etc.). It would have been almost unthinkable, and was indeed rare to dispatch a halakhic query from Spain to Ashkenaz and vice versa. This fragmentation was not due only to communication barriers, but mainly because they were considered as distinct halakhic heritages. The fragmentary character continued to a large extent in early modern period, though there was a slow but steady shift toward supra-local institutions. R. Karo's attempt to found a new type of court that was intended to extend its authority beyond the Muslim lands, which relates precisely to this course of change. Like other elements in his grand program, it was not a completely new pattern, but neither was it a mere continuation. The innovative dimension was the aspiration to serve the entire Jewish Ecumene; in other words, Karo sought to establish an international court of law—the first in Jewish tradition since the Gaonic period of late antiquity. An international legal pattern of this kind evolved in the European context, and following the colonial expansion in the New World, inspired by legal-theological discussions of the “Second Scholasticism.” No less significant in this context are the changes in the Ottoman Empire at the time, following its impressive expansion into new territories, and accompanied by the imposition of the same state law in all the territories under Ottoman rule. State law was international in its special extent, and the Ottoman courts adjusted to the same legal traditions across the empire.

International Law in European and Ottoman Empires

The rise of international law, as practiced today by the United Nations, the International Court of Justice, and similar institutions, is described in most current research as a derivative of political and ideological changes in early modern European history. Scholars of international law, in its various domains, are predominantly interested in the rise of modern centralist states and the unprecedented colonial expansion of some European grand states—such as Spain and England—into the New World.