On May 18, 1096, Crusaders massacred Jews in Mainz, Metz, and Worms. From the article:
"This Day in Jewish History / Crusaders massacre the Jews of Mainz
At least 600 Jews are thought to have died in one of the first events of the First Crusade.
On May 27, 1096, a Crusader army led by Count Emicho of Flonheim entered the walled Rhineland city of Mainz, hunting down and killing Jews.
The Mainz massacre, in which an estimated 600 Jews were murdered (although some reports put the number at over 1,000), was one of a number of attacks on Germany’s Jews by bands of armed peasants from France and Germany, at the start of what came to be known as the First Crusade.
The Jewish communities of Metz, Speyer and Worms were also targeted. The Crusaders generally sought to convert Jews or to take their money, which they used for provisions for the battles ahead.
Each of the chroniclers – Christians and Jews, some of them writing at around the time of the events and others only years later – had different motivations in writing, and they don’t always agree on even the simplest facts.
The 11th-century Jewish scholar Solomon bar Simson argued that Emicho had had a vision of himself as the “Last Emperor,” a popular apocalyptic concept of the era. The Last Emperor was someone who would bring about the conversion of the Jews and then lead a united Christendom to Jerusalem, to conquer it and usher in the End of Days. It was that vision, suggest some historians, that inspired not only Emicho but also the thousands who joined his army to begin the long march eastward.
Kenneth Stow, professor emeritus of Jewish history at the University of Haifa, disagrees with this characterization of Count Emicho. He suggests that bar Simson was mocking Emicho, whom he and other chroniclers were angry at for their feeble attempts at converting the Jews. Stow believes that, from a medieval Christian perspective, it was worse to force Jews to undergo baptism under the threat of death and run the risk of having them abandon their Christianity and return to Judaism than it was to leave them be. “This ‘backsliding,’ as it was called, was opprobrious,” Stow wrote, in a 2001 article, as it “led to the violation not only of the canons forbidding apostasy but also of the canons protecting the Jews and their right to preserve their religion.”
In any event, Emicho and his army found themselves locked out when they arrived at the gates of Mainz on May 25. The Jews inside tried negotiating with him, and even delivered a ransom of gold. Archbishop Ruthard of Mainz offered the town’s Jews refuge in his palace. Some of Mainz’s burghers of Mainz offered protection to Jews with whom they did business, and an effort was even made to organize armed resistance to the crusaders.
But the crusaders were too numerous to defeat, and by the time they entered the city the archbishop and his militia had fled. The crusaders combed the archbishop’s palace and the home of the burgrave, the military governor of the city, and killed the Jews they found who hadn’t already killed themselves. Memorial books commemorating the slaughter list the names of more than 600 Jewish victims.
After Mainz, Emicho’s army proceeded through the Rhine Valley, by way of Cologne, toward Hungary. Emicho was killed in battle by the Duke of Swabia. His followers met their end at the hands of Hungarians, in Wieselburg, near Bratislava – never coming anywhere near the Holy Land."