As Christianity and Islam gained political power, the Jews found themselves caught in the middle of violent conflict. Rabbi Wein traces the emigration patterns of the Jews from Babylonia to North Africa to Europe, describing how they adapted in their "host" countries. Religious, economic, and social forces shaped the two streams of the Jewish world: the Ashkenazic and Sephardic communities. Out of each emerged the two great pillars of Torah: Rashi and Rambam.