The official church policy at the time was to protect Jews because Jesus was born into the Jewish race , but in reality Jews were often targets of Christian loathing . As the plague swept across Europe in the mid-14th century , annihilating nearly half the population , people had little scientific understanding of the disease and were looking for an explanation . Jews were often taken as scapegoats and accusations spread that Jews had caused the disease by deliberately poisoning wells . This is likely because they were affected less than other people , many Jews chose not to use the common wells of towns and cities and because Jews confessed to poisoning water under torture . The first massacres directly related to the plague took place in April 1348 in Toulon , Provence , where the Jewish quarter was sacked , and forty Jews were murdered in their homes , then in Barcelona . In 1349 , massacres and persecution spread across Europe , including the Erfurt massacre , the Basel massacre , massacres in Aragon , and Flanders . 2,000 Jews were burnt alive on 14 February 1349 in the " Valentine 's Day " Strasbourg massacre , where the plague had not yet affected the city . While the ashes smouldered , Christian residents of Strasbourg sifted through and collected the valuable possessions of Jews not burnt by the fires . Many hundreds of Jewish communities were destroyed in this period . Within the 510 Jewish communities destroyed in this period , some members killed themselves to avoid the persecutions . In the spring of 1349 the Jewish community in Frankfurt am Main was annihilated . This was followed by the destruction of Jewish communities in Mainz and Cologne . The 3,000 strong Jewish population of Mainz initially defended themselves and managed to hold off the Christian attackers . But the Christians managed to overwhelm the Jewish ghetto in the end and killed all of its Jews
Erfurt massacre
Erfurt massacre (1349)
Black Death Jewish persecutions