It offers the keys to understand the antiJudaism that has impregnated the political and social history of Spain. The author, Pere Bonnín, a descendant like many intellectuals- even if they are not aware of it- of converted Jews, explains in this singular book what the practice of Judaism consists of. Then he revises the history of Christian anti-Semitism from the gospels up to its current importance, when both the Vatican and the Spanish Monarchy, which was once the military wing of the Catholic Church, have reconciled with Judaism.