Pius XII (Eugenio Pacelli) went through the most difficult years of the European and world history of the 20th century. He came to supreme responsibility in the Church with a long diplomatic experience. His figure, in a crucial period for the history of the world, stood tall at the head of the great force of world Catholicism, drawing attention for the austerity of his life, for the successes in the government of the Church, for his actions and above all, the political problems of the world. Everyone had to admit it and even the diatribes of the Vatican's opponents —such as the attacks by the communist and anticlerical press— were very powerful arguments that enlarged the role played by Pius XII. His voice, lonely in the silence and darkness into which Europe fell, was that of the only sovereign on the continent who had the courage to ask for respect for treaties, an end to aggression, equal treatment for minorities and cessation of religious persecution. No one but Pius XII was able to speak for peace. This book, divided into two parts, offers in the first one a summary of his pontificate, highlighting his attempts to prevent World War II, his public interventions against the conflict, the humanitarian work of the Holy See, the Pope's fight against paganism and atheism, and against communism. In the second, centered on the title of the book, it is affirmed that Pius XII made more efforts in defense of the Jews than any humanitarian organization, the great work of assistance in favor of the Jews is documented and the black legend is analyzed on the attitude of Pius XII. The question is answered: when was this legend born and what may have been its causes? Testimonies of Jews about the Pope and the most recent documents that confirm that he generously helped the Jews are provided. Pius XII has been accused of silence in the face of that tragedy, but he concluded that an act of public protest on his part would not have achieved the slightest result and would certainly have aggravated the persecution. In addition, a public protest would have prevented the Church from carrying out its hidden work of assistance to the Hebrews.