On May 18, 1096, Crusaders massacred over 800 Jews in Worms, Germany. A short excerpt:
"On May 18, 1096, Christians in Europe heeded the call of Pope Urban II and joined up with the throngs following local noblemen in a Crusade to regain the Holy Land of Jerusalem from the Muslims that occupied what is now Israel and the Levant, but on this day the Crusading zeal went in a horribly different direction.
Digging Deeper
Count Emicho of Leiningen had gathered his forces to serve the cause of God in the People’s Crusade (First Crusade), though it seems his personal goal was to rid Germany of its Jewish population. On May 18, 1096, he led his men in a wholesale slaughter of 800 Jews in the city of Worms, just one of many such massacres (pogroms) of Jews in actions called the “Rhineland Massacres” led by Count Emicho and other Crusader leaders such as Peter the Hermit."