On the eve of our period, much of western Europe had already lost its Jews, following expulsions from England, France, the Low Countries, and certain German lands. The greatest and most notorious expulsion came when Spain’s Jews were expelled in 1492 – an event often used to mark the start of the early modern period. Many of the exiles moved across the border into Portugal, but they became “New Christians” (or “conversos”) when they were forcibly converted to Catholicism en masse in 1497. However, most of the exiles left the Iberian Peninsula altogether and migrated throughout the Mediterranean region, settling in North Africa, Italy, and the Ottoman Empire.
Well before this, Ashkenazi Jews had already begun to immigrate to eastern Europe (and to a lesser extent to Italy), as medieval anti-Jewish sentiment and economic opportunities elsewhere drove them out of German lands. By the end of the fifteenth century more than 60 Jewish communities existed in Poland-Lithuania, scattered from Breslau and Gdansk in the west to Kiev and Kamenets Podolski in the east. The great wave of Ashkenazi expansion eastward, however, came with the union of the kingdoms of Poland and Lithuania in 1569, and with the intensive colonization of the Ukraine that followed. By the end of our period, Poland-Lithuania possessed the largest concentration of Jews in the world.
From the late fifteenth century, a steady stream of New Christians escaping Spain and Portugal joined Sephardi communities in the Mediterranean area. But from the mid-sixteenth century onward they began making their way to new Atlantic trade centers to the north, first as New Christians and then, when conditions permitted it, as openly practicing Jews. They settled in Bordeaux, Bayonne, Hamburg, Amsterdam, London, and other towns. Some New Christians had already settled in Brazil and Spanish America; in the seventeenth century, Jews from the Netherlands and elsewhere settled in Dutch Brazil, New Amsterdam, the East and West Indies, and West Africa.
While these Sephardim were the first to resettle areas of Europe from which Jews had fled in the medieval period, the Ashkenazim soon followed. By the seventeenth century, German rulers seeking to rebuild war-torn central Europe began allowing Jews to settle in towns and villages from which they had once been expelled. Gradually, new Ashkenazi communities were established, not only in the German states but in the Netherlands and England as well.