From the mid-twelfth century onward urban communities scattered across Europe persuaded themselves that each year about Eastertime the Jewish minorities living among them conspired in the systematic abduction and ritual slaughter of Christian children. That myth would be used to justify centuries of harassment, robbery, and judicial murder of European Jews. Jews, it was claimed, believed that their ultimate return to the Holy Land depended on the spilling of innocent Christian blood. Alternatively, it was suggested, Jewish Passover rituals involved the baking and consumption of matzoh that had been mixed with human blood. Jewish medicine and Jewish magical healing were thought to require the blood of children.

Underpinning all these beliefs was the long-standing accusation that the Jewish people collectively were guilty of deicide—God-murder—in bringing about the death of Christ, and now, maliciously and “in mockery of the Passion,” sought endlessly to renew that sin by inflicting the pains of crucifixion on the bodies of Christian children. More than a century after the Jews had been banished from medieval England, Geoffrey Chaucer would enshrine one such horrific story of Jewish murder in his Prioress’s Tale, and would invoke another, the supposed killing in 1255 of “yonge Hugh of Lincoln, slayn also/with cursed Jewes.”

Fostered by a grotesque farrago of ignorance and misinformation about Jewish ritual practices, religious and racial prejudice, and economic resentment, this charge of Jewish ritual murder, the so-called blood libel, persisted and ramified down the years. A Jewish survey of such allegations compiled in the early twentieth century listed six…