While Pius XII is most commonly considered the "World War II Pope," his predecessor, Pius XI, fought the rise of Hitler and Mussolini from the start. In his book, "The Pope's Last Crusade," Peter Eisner discusses how Pius XI enlisted the aid of an American priest to write a papal condemnation of their ideologies. The effort was done largely in secret to avoid political infighting, yet Eisner's version includes backroom intrigue among the few Vatican officials who were in the know. There were justifiable concerns about provoking Hitler and about Mussolini's Italian government, which was just outside the Vatican's front door. Much of this story was unknown until the 1970s and is still the cause of debate and speculation.
--Michael B., Jamestown Bluffs Branch