In the meantime, the devastating war broke out between the fierce Hussites and the not less barbarous Roman Catholics, between the Czechs and the Germans. A variety of nationalities participated in the sanguinary struggle as to the use of the cup by the laity in the eucharist. Emperor Sigismund, who found it impossible to subdue the insurrection with his own troops, summoned the imperial army to his standard. Wild free-lances, men of Brabant and Holland, were taken into his pay. From all quarters armed troops poured into the Bohemian valleys and against the capital, Prague, where the blind hero, Zisca, bade defiance to a world of foes. On the way, the German imperial army exhibited its courage by attacks on the defenseless Jews. "We are marching afar," exclaimed the mercenaries, "to avenge our insulted God, and shall those who slew him be spared?" Wherever they came across Jewish communities, on the Rhine, in Thuringia and Bavaria, they put them to the sword, or forced them to apostatize. The crusaders threatened, on their return from victory over the Hussites, to wipe the Jewish people from the face of the earth. Jewish fathers of families true to their faith gave orders that, at a certain signal, their children should be killed to avoid falling into the hands of the bloodthirsty soldiery. Letters of lamentation over the threatened disaster, calling upon him to implore the intervention of heaven, were addressed from far and near to the illustrious rabbi of Mayence, Jacob ben Moses Mölin Halevi (Maharil, born 1365, died 1427), the most pious rabbi of his time. His arrangement of the synagogue ritual and melodies is used to this day in many German communities, and their colonies in Poland and Hungary. Jacob Mölin ordered a general fast, accompanied by fervent prayer, and his instructions were circulated from one community to another throughout the land. The German congregations forthwith assembled for solemn mourning and humiliation, and fasted during four days between New Year and Atonement (8th-11th September, 1421), and for three successive days after Tabernacles, the observance being as strict as on the most sacred fast days of the Jewish calendar. It was a time of feverish tension for the German Jews. In their despair they prayed that victory might be vouchsafed to the Hussites, and it seemed as if their supplications were heard. For, shortly afterwards, the imperial army and its mercenary allies assembled near Saatz were stricken with such terror at the news of Zisca's approach, that they sought safety in disorderly flight, disbanding in all directions, and hurrying home by different routes. Famished and footsore, a few of the very men who had vowed death and extirpation to the Jews, appeared at the doors of their houses, begging for bread, which was gladly given them. Privation had so reduced the fugitives that they could not have harmed a child.