The blood libel originated in beliefs about male Jewish menstruation

Evidence

The ancient fantasy of male Jews bleeding regularly had been the origin of the idea of Jewish ritual murder from early modern times to the present. Jewish men were believed to need Christian blood to “heal” their bloody discharge. This view persisted into the late nineteenth century. — Ivan Davidson Kalmar, Derek Penslar, Orientalism and the Jews, 730

Categorization

• CANDY: The baroque rationale behind the blood libel — that Jewish men bleed and need Christian blood to heal — is a striking conversational fact.
• QUESTION: Worth tracing the fuller genealogy from male menstruation myth into the blood-libel accusation literature.
• corroborated: 4 independent passages support this claim — Ivan Davidson Kalmar, Derek Penslar, Orientalism and the Jews, 730
• XREF: connects to: Menstrual contamination beliefs survived into modern industrial practice and law — Simone de Beauvoir, The Second Sex, 336