Blood libel is a false accusation that Jewish people murder Christian children to use their blood in religious rituals. This myth has been used throughout history to justify discrimination and violence against Jewish communities. The origins of blood libel date back to the Middle Ages, particularly in Europe, where it fueled anti-Semitic sentiments. Notable cases, such as the William of Norwich incident in 1144, spread fear and led to brutal consequences for Jewish populations, including massacres and expulsions.