The existence of Jewish settlements in Germany early in the 4th century has been established by historical evidence. Reference to Jews in Cologne is found in decrees issued by Emperor Constantine. Earlier, Jewish traders had followed in the footsteps of the Roman legions who established military outposts along the northern ports of the Rhine. Little is known about the fate of the Jews in Germany at the time of the fall of the Roman empire and during the succeeding invasions from the East and West. During the reign of Charlemagne (771-814), the Jews engaged in commerce and trade. He found Jews useful to the welfare of the state and protected them against undue discrimination. His son Louis the Pious (814-840) extended commercial privileges to Jews. Their importance in the economic field is illustrated by the fact that on many occasions market-day was postponed from a Sabbath to a weekday in order to enable Jews to participate in it. Often, Jews were invited to settle in particular towns in order to increase their prosperity. In the 9th and 10th centuries Jewish communities sprang up in the cities of Augsburg, Mayence, Regensburg, Speyer, and Worms.

The development of Jewish economic life paralleled intensive scholarly activity. The famous family of Kalonymus, a family of scholars and poets, moved from Italy to Germany. One of the greatest authorities on Jewish law, Rabbenu Gershom, called “the Light of the Exile,” headed a Talmudic academy, or yeshiva, in the city of Mayence, attracting students from distant countries.

In the Middle Ages. The First Crusade in 1096 brought about the destruction of a number of Jewish communities. A number of elegies included in the Book of Lamentations chanted on the Ninth of Av bemoan the tragedy of that period. The Second Crusade in 1146, although less severe in its effect on Jewish communities, led to a worsening of the Jewish economic position. Jews became chattels of the kings, who extended them protection against the attacks of fanatic mobs at the price of their freedom and only in exchange for a heavy tribute.

This humiliating status did not save the Jews from cruel discriminations. In the 13th century, Jews were forced to wear a degrading yellow badge. They were forbidden to hold public office. Ritual murder accusations were leveled against them, even though these were denounced by Pope Innocent IV.

Persecutions of Jews increased at the time of the plague known as the Black Death from 1348-49. The Jews were accused of having caused the plague by poisoning the wells. The resulting widespread pogroms in many German towns caused Jews to seek shelter in Slavic countries. In 1421, Jews were expelled from Cologne. During the next two centuries, the Jewish population continued to be victimized with blood accusations, confiscations of property, forced baptism, burning of Jewish books, and physical attacks. The banishment of the Jews from important centers of trade and commerce