This book, published in 1982, stirred controversy. It argued that the blood libel, a false accusation against Jews of using the blood of Christian children in religious rituals, originated from a medieval Christian slander and was not a reflection of actual Jewish practices.
Toaff's book is considered a significant contribution to understanding the history of antisemitism and has been both praised and criticized for its analysis.
Note: There is another author, Eli Toaff, a writer of children's books. If you were thinking of him, please let me know and I can provide more information.