All the Jewries of northern Europe were new, much newer than the Jewish communities of the south. The Jewries of northern Europe did not have roots in the Roman world; they were not located in areas conquered and held by the Byzantines or the Muslims; they did not build a reservoir of experience under the rule of these conquerors; there was no experience of Christian reconquest to affect them for good and ill. Northern-European Jewish life was a tabula rasa, a blank slate to be shaped by the interaction of Christian majority and Jewish immigrant minority during our period, influenced to be sure by prior Church doctrine, policy, and imagery with respect to Judaism and Jews.

What is so striking about the evolution of northern-European Jewry is that, alongside the broader shift of the center of gravity in the Jewish world from the realm of Islam to western Christendom, there was an internal shift as well, as the Jewries of northern Europe began the slow process of exceeding the Jewries of the south in size and power. While the Jewish experience in northern Europe was decidedly mixed, with much that was negative from the Jewish perspective, the Jewish immigrants to the northern lands and their Christian neighbors were successful in laying the groundwork for the emergence of what is often designated Ashkenazic Jewry, which became the dominant Jewish sub-group on the modern scene.