Attacks On The Jewish Communities In France And Germany
At a local level, the preaching of the First Crusade ignited violence against Jews, which some historians call "the first Holocaust". At the end of 1095 and beginning of 1096, months before the departure of the official crusade in August, there were attacks on Jewish communities in France and Germany. In May 1096, Emicho of Flonheim (sometimes incorrectly known as Emicho of Leiningen) attacked the Jews at Speyer and Worms. Other unofficial crusaders from Swabia, led by Hartmann of Dillingen, along with French, English, Lotharingian and Flemish volunteers, led by Drogo of Nesle and William the Carpenter, as well as many locals, joined Emicho in the destruction of the Jewish community of Mainz at the end of May. In Mainz, one Jewish woman killed her children rather than see them killed; the chief rabbi, Kalonymos, was also killed.
The call for the First Crusade touched off new persecutions of Jews in which peasant crusaders from France and Germany attacked Jewish communities.
The preaching of the First Crusade inspired an outbreak of anti-Semitism. In parts of France and Germany, Jews were perceived as just as much an enemy as Muslims: they were thought to be responsible for the crucifixion, and they were more immediately visible than the distant Muslims. Many people wondered why they should travel thousands of miles to fight non-believers when there were already non-believers closer to home.
Wikipedia: First Crusade
Wikipedia: Persecution Of Jews In The First Crusade