In June 1938, John LaFarge, an unassuming American Jesuit priest and scholar, was summoned to a private audience with Pope Pius XI. Inspired by LaFarge’s book, Interracial Justice, which argued that “racialism and nationalism were fundamentally the same,” the pope enlisted the priest to pen a papal encyclical—a declaration of the Catholic Church’s official view—condemning Nazism and anti-Semitism. A profoundly moral and devout man, Pius XI hoped that this official decree, the highest public statement expressed by the Holy See, would raise public opposition to the Third Reich and compel world leaders to challenge Adolf Hitler and his allies before it was too late.

A shocking tale of intrigue and suspense, illustrated with sixteen pages of photos, The Pope’s Last Crusade illuminates this religious leader’s daring yet little known campaign to fight Hitler, a spiritual and political battle that would be derailed