original text. Halakhic studies began to flourish about 1000. At that time, Rav Gershom ben Judah was teaching at Metz and Mainz, gathering about him pupils from far and near. He is described in Jewish historiography as a model of wisdom, humility, and piety, and became known to succeeding generations as the "Light of the Exile". In highlighting his role in the religious development of Jews in the German lands, The Jewish Encyclopedia (1901–1906) draws a direct connection to the great spiritual fortitude later shown by the Jewish communities in the era of the Crusades: He first stimulated the German Jews to study the treasures of their religious literature. This continuous study of the Torah and the Talmud produced such a devotion to Judaism that the Jews considered life without their religion not worth living; but they did not realize this clearly until the time of the Crusades, when they were often compelled to choose between life and faith. Cultural and religious centre of European Jewry The Jewish communities of the cities of Speyer, Worms, and Mainz formed the league of cities which became the center of Jewish life during Medieval times. These are referred to as the ShUM cities, after the first letters of the Hebrew names: Shin for Speyer (Shpira), Waw for Worms (Varmaisa) and Mem for Mainz (Magentza). The Takkanot Shum ( "Enactments of ShUM") were a set of decrees formulated and agreed upon over a period of decades by their Jewish community leaders. The official website for the city of Mainz states: Historian John Man describes Mainz as "the capital of European Jewry", noting that Gershom ben Judah "was the first to bring copies of the Talmud to Western Europe" and that his directives "helped Jews adapt to European practices." Gershom's school attracted Jews from all over Europe, including the famous biblical scholar Rashi; and "in the mid-14th century, it had the largest Jewish community in Europe: some 6,000." "In essence," states the City of Mainz web site, "this was a golden age as area bishops protected the Jews resulting in increased trade and prosperity." A period of massacres (1096–1349) The First Crusade began an era of persecution of Jews in Germany, especially in the Rhineland. The communities of Trier, Worms, Mainz, and Cologne, were attacked. The Jewish community of Speyer was saved by the bishop, but 800 were slain in Worms. About 12,000 Jews are