Blood libels typically claim that Jews require human blood for the baking of matzos, an unleavened flatbread which they eat during Passover, although this element of the accusation was allegedly absent in the earliest blood libels in which then-contemporary Jews were accused of reenacting the crucifixion of Jesus. The accusations often assert that the blood of the children of Christians is especially coveted, and, historically, blood libel claims have been made in order to account for the otherwise unexplained deaths of children.
In some cases, the alleged victims of human sacrifice have become venerated as Christian martyrs. Three of these – William of Norwich, Little Saint Hugh of Lincoln, and Simon of Trent – became objects of local cults and veneration; and although he was never canonized, the veneration of Simon was added to the General Roman Calendar. One child who was allegedly murdered by Jews, Gabriel of Białystok, was canonized by the Russian Orthodox Church.
Similar tactics were in use in innumerable dictatorships throughout history and continue to be used by destructive cults and hate groups. It was a common propaganda tactic used by the Nazi Party during the Holocaust and is also frequently used by various Alt-Right and Militant Islam groups during the present day.