In the latter half of the fifteenth century Joseph Colon wrote a volume of responsa. His opponent was Elijah Kapsali. Of special interest in Colon’s decisions is the case of the congregation of Nuremberg, in which he held that all German congregations were obliged to contribute toward the expenses of the trial of Israel Bruna, who was accused of complicity in the murder of a Christian child in 1477. In Germany the most important rabbi of the fifteenth century was Israel Isserlein of Marburg, 1400-1470, author of Terumat Ha-Deshen, a collection of responsa containing important historical notes. When the authorities in Breslau issued a law that Jews had to swear with uncovered head and by the name Yahve, he permitted it, provided it was not meant as an attempt to convert the Jews. The German and French rabbis in the thirteenth century were characterized by their strict adherence to authority and rigorous view of the law. The most prominent is Judah ben Samuel Hechasid, author of “Sefer Hasidim.” Eleazar ben Jehudah of Worms, a descendant of the Kalonymos family, and author of Rokeah (druggist), is a type of this ascetic school. Another is Moses of Coucy, author of a compendium of the 613 commandments Sefer Mizwot Haggadol, abbreviated Semag. In the thirteenth century the study of Kabbala received strong impetus from Isaac, the blind, son of Rabed. His disciples were Ezra and Ezriel; their disciple was Ramban, and he introduced Kabbala into his commentary on the Pentateuch. About 1390 Moses of Leon wrote the Zohar, a Kabbalistic Midrash on the Pentateuch, which he claimed was written by Simeon ben Yohai, disciple of Akiba, and discovered by him in a cave. It is written in Aramaic. CHAPTER VII THE PERIOD OF IMPROVEMENT (1492-1791)