On hearing of the pope's death, Mussolini commented, "At last the obstinate old man is dead." Perhaps, worse was to come with his successor - certainly for the Jews. Kertzer argues that, despite having irrefutable evidence of the ongoing extermination of the Jews, Pacelli (now Pius XII) never denounced the Nazi atrocities, as he preferred to leave the role of moral guide, rather than put at risk the situation of the church. Moreover, Pius XII spoke with much sympathy for Fascism and with sincere admiration for the Duce...as for Germany, the new pope could not be more eager to come to an agreement. His sainthood is still being discussed; it will say much about the Roman Catholic Church if he receives it.
John Cornwell, Hitler's Pope: The Secret History of Pius XII (1999)
Eamon Duffy, Saints and Sinners. A History of the Popes (2006)
David I. Kertzer, The Pope who would be King: The exile of Pius IX (2018)
Frédéric Martel, In the Closet of the Vatican: Power, Homosexuality, Hypocrisy (2019)
FOOTNOTE
Just out of interest, I thought I would look up the twelve popes who assumed the name Pius. Between the first and second was over 1,000 years; there were four between 1458 and 1572; then a 200-year gap until a flurry of another four between 1775 and 1878; finally, the three in the 20th century. The last four with the name, the IXth to XIIth, are, perhaps, the most controversial.
Pius I (c.142-c.155) - opposed the heresy of the Gnostic Marcion. - 1,300 years before the next Pius! Pius II (1458-64) - patron of the arts; canonized St. Catherine of Siena, regularly called for a crusade, guilty of nepotism. Pius III (1503) - 10 day reign, ill health, but man of culture and integrity. Pius IV (1559-65) - father of three illegitimate children, vigorous benefactor of his many relatives, reconvoked and concluded the Council of Trent. Saint Pius V (1566-72) - guilty of nepotism, strengthened Rome's fortifications, excommunicated Elizabeth, revived savage use of the Inquisition, harsh treatment of the Jews. Pius VI (1775-99) - weak, vain and worldly; revived nepotism, spent lavishly on buildings, appeared grasping; arrested by Napoleon, died in prison. Pius VII (1800-23) - crowned Napoleon; rehabilitated the Jesuits, reintroduced the Holy Office, founded the Vatican Picture Gallery. Pius VIII (1829-30) - traced breakdown of religion to activities of Protestantism, Freemasonry and secret societies. Pius IX (1846-78) - believed temporal sovereignty of the holy see indispensable to its spiritual independence; 1860 lost all his dominions save Rome; 1870 lost all but the Vatican area; centralised authority; created over 200 new bishoprics or apostolic vicariates; unprecedented number of canonisations; declared infallibility of the pope in faith and morals in their own right; against modern political and intellectual trends; pro ultramontanism. Saint Pius X (1903-14) - canonised by Pius XII. Aimed to insist unyieldingly on the church's rights; anti Modernism; (they should be beaten with fists) harassed scholars; paternalistic; reorganised the Curia. Pius XI (1922-39) - believed church and Christianity should be active in society; delegated as little as possible, dictatorial; he had not a liberal bone in his body; greatly reduced role of the sacred college. Pius XII (1939-58) - proclaimed the Dogma of the Assumption of the Virgin Mary; inveighed against communism; canonised 33 persons and created an unprecedentedly large number of cardinals; authoritarian in style.