The essay concentrates on a product of the twelfth century, the first—known—attempt to accuse Jews of the murder of a Christian child, on behalf of all Jews. It is the beginning of what would later—in the course of the thirteenth century—become a more elaborate narrative that linked such murder to the needs of Jewish ritual. Miri Rubin discusses what we are to make of this novelty and what the conditions of possibility were out of which it emerged. Furthermore, the author discusses what were to become its legacies and aftermath.