Some Jewish communities were given trouble simply by mention of the plague. Zurich in Switzerland banned all Jewish people over a year before the plague reached the city.
The idea that Jews were responsible for the Black Death took root in Southern France and Spain. A third of the 2.5 million Jews lived in these areas and had mounting tensions with neighboring Christians.
The Jewish communities all over Europe were torn to pieces by a populace crazed by the plague. Emperor Charles IV granted immunity to the attackers and conceded Jewish property to his favorites.
The Black Death led to the first expulsion of the Jews from Hungary in 1349. A general expulsion was decreed in 1360, but in about 1364 their return was authorized though they were subjected to restrictions.
People massacred Jewish people in large numbers during the Black Death era. On 9 January 1349, approximately 600 Jews were gathered in a wooden house, specially constructed for the purpose, on an island in the river Rhine. There they were burned.
After one tortured Jew “confessed” to poisoning the wells, pogroms occurred in many towns in Northern Europe. Switzerland, Northern France, Germany, and the Low Countries witnessed attacks, often before the Black Death reached them.
When the Black Death was progressing from Spain and Italy north to England and Poland, about 300 Jewish communities were attacked and thousands of Jews were burned at the stakes or killed. In the German states almost all Jewish communities were expelled.
Christians fingered the Jewish community for the Black Death as a means of retribution. Many believed that Jewish communities were taking revenge for decades of anti-Jewish hostility by poisoning the wells and water supplies.
The lower incidences of the Black Death among the Jewish population might have led to suspicions about their involvement as well. By the time of the outbreaks, the Jews were exclusively urbanized and segregated into their own districts within cities. Living in these separate areas, the Jews were cut off from the rodents around the waterfront and the cattle in the countryside.
There was a widespread belief that the Black Death was caused by Jews poisoning wells and local water
supplies. Part of this suspicion was due to religious and economic reasons. Many Christians saw the Jew's practice of the Kaballah, with its mystical and astrological components, as constituting a kind of black magic.