The history of European Jewry over the last two hundred years divides into three periods or, to be more exact, has followed three distinct but overlapping patterns of development. The original mode of Jewish life as it existed throughout most of Europe in the early eighteenth century was still medieval. Juridically defined as a separate community in the hierarchy of different orders and estates, assigned specific economic functions, possessed of its own languages (Yiddish and Hebrew) and laws (those administered by the rabbinical authority), the Jewish people from the Rhine to the Dnepr formed a highly conservative (albeit not unchanging), inward-looking, and self-contained entity.

A new historical process, which drove an ever wider breach through the walls of this medieval community, was set in motion under the combined impact of the Enlightenment–known in the Jewish world as the Haskala – and the various governmental acts of emancipation. The idea of one law for all and equality before that law was carried eastward by the French armies of the revolution and Napoleon; and even though that program was not fully carried out anywhere in central or eastern Europe, no state there failed to implement it in part.

Increasingly, throughout the early and mid-nineteenth century, a sharply contrasting way of life emerged in the Jewish world alongside the old.