As plague spread through Europe in 1348 and 1349, Jewish communities were accused of causing it by poisoning wells. Confessions extracted under torture at Chillon on Lake Geneva in September 1348 were circulated to towns along the Rhine and became the template for the accusation. Pope Clement VI issued two bulls condemning the charge and pointing out that Jews were dying of the plague as well, without effect. At Basel in January 1349 the community was burned in a wooden house built for the purpose; at Strasbourg on 14 February 1349, before the plague had even reached the city, several hundred to two thousand Jews were burned and the survivors expelled, after a coup by the guilds against a council that had protected them. Similar destructions followed at Mainz, Cologne, Erfurt, Frankfurt, Brussels and hundreds of smaller places. Municipal debt to Jewish lenders was extinguished along with the lenders in many cases. Surviving communities were expelled and moved east, reshaping the geography of Ashkenazi Jewry.
Town councils, guilds, flagellant bands and local lords across the Holy Roman Empire, the Rhineland, Alsace, Switzerland, Aragon and Provence killed, burned or expelled Jewish communities accused of poisoning wells during the plague
There is no census; Salo Baron's estimates and later work on the Memorbücher and town records put the Jewish population of the German lands at roughly 80,000-150,000 in the mid-fourteenth century, spread over some 1,000 settlements, of which more than 500 communities were destroyed or dispersed in 1348-51.
No defensible aggregate exists. Individual episodes are documented — Strasbourg's is variously given as several hundred to two thousand, Basel's as several hundred — and the memorial books name thousands of dead across hundreds of localities, but no scholar has produced a total for the wave as a whole.
The burnings of whole communities, the extraction of confessions under torture at Chillon and the seizure and destruction of Jewish property are documented in municipal records, the Chillon depositions, the memorial books and contemporary chronicles.
France, Poland