Jewish Cities in Europe in 1800 with a Map

This is not true. There were few Jews in Eastern Europe before the 1300s/1400s. Widespread violence against western European Jews started in the 1300s. French cities were among the first locations to commit massacres. During the Strasbourg Massacre, thousands of Jews were burned alive for the public to see. This is largely because of myths, including the blaming of Jews for the plague, the blood libel myth, and the host desecration myth. Jewish populations in Western Europe began fleeing violence and systematic oppression towards the east, where it was relatively more tolerant. As large numbers arrived, Eastern European antisemitism grew, and the tsarist regime conducted brutal massacres of its own, albeit hundreds of years later.