The Dominican clergy commissioned to preach against the Hussites did not cease to foster Catholic hatred of Jews. From their pulpits they thundered against heretics and Jews alike, cautioning the faithful against holding intercourse with them, and consciously and unconsciously inciting to attacks on their persons and property. The Jews flew for help to the pope, Martin V--doubtless not with empty hands--and again obtained a very favorable bull (23d February, 1422), in which Christians were enjoined to remember that their religion had been inherited from Jews, who were necessary for the corroboration of Christian truth. The pope forbade the monks to preach against intercourse between Jews and Christians, and declared null and void the ban with which transgressors had been threatened. He recommended to Catholics a friendly and benevolent attitude towards their Hebrew fellow-citizens, severely denounced violent attacks upon them, and confirmed all the privileges which had from time to time been granted by the papacy. This bull was, however, as ineffectual as the protection which Emperor Sigismund had so solemnly promised the Jews. A persecuting spirit continued to animate the Christian church. The monks did not cease to declaim against the "accursed" Jewish nation; the populace did not refrain from tormenting, injuring and murdering Jews; even succeeding popes ignored the bull, and restored the odious canonical restrictions in all their stringency. Turning a deaf ear to both pope and emperor, the citizens of Cologne expelled the Jewish community, perhaps the oldest in Germany. The exiles took up their abode at Deutz (1426). In the South German towns, Ravensburg, Ueberlingen and Lindau, the Jews were burnt because of a lying blood accusation (1431).
The literary work of the German Jews was, as a consequence, poor and inconsiderable. Anxiety and persecution had deadened their intellect. Even in Talmudical study the German rabbis hardly rose above mediocrity, and gave nothing of consequence to the world. Some rabbis were installed by the reigning prince; at least Emperor Sigismund commissioned one of his Jewish agents, Chayim of Landshut, "to appoint three rabbis (Judenmeister) in Germany." Under such auspices, appointments were probably determined less by merit than by money. For a college, in which students were prepared for the rabbinate, a heavy tax had to be paid, notwithstanding that the instruction was given gratuitously. Besides Jacob Mölin, only one name of importance emerges from the darkness of this period, Menachem of Merseburg, or, as he was generally called, Meïl Zedek. He wrote a comprehensive work on the practice of the Talmudic marriage and civil law, which the Saxon communities adopted for their authoritative guidance. He, at least, departed from the beaten track of his older contemporaries or teachers, Jacob Mölin and Isaac Tyrnau, who attached value to every insignificant detail of the liturgy. By and by Menachem of Merseburg was recognized as an authority, and an excellent regulation drawn up by him received universal assent. Among the Jews at that period, marriages took place at a very early age; girls in their teens were hurried into matrimony. According to Talmudical law a girl, under age, who had been given in marriage by her mother or brothers and not by her father, was permitted, on attaining her majority, in her twelfth year, and even much later under some circumstances, to dissolve her union without further ceremony than a declaration of her intention to do so, or the contracting of another marriage (Miun). Menachem of Merseburg felt the indecency of so sudden and often capricious a dissolution of marriage, and he decided that formal bills of divorce should be required.