https://www.reformation.org/holoc1.html
The Vatican and Fascism helped each other from the beginning. Pope Pius XI (1922-1939) ordered the Leader of the Catholic Party to disband it (1926), the better to consolidate the regime of Mussolini. The latter negotiated the Lateran Treaty and Concordat with the Church (1926-1929).
By virtue of the first, the Vatican became a sovereign state within Rome. While with the second, the Church was granted immense privileges and Catholicism was declared the only religion of Fascist Italy, which it wholeheartedly supported.
Bishops took an oath of allegiance to the Fascist Dictatorship, and the clergy were ordered never to oppose it or incite their flock to harm it. Prayers were said in Churches for Mussolini and for Fascism. Priests became members of the Fascist Party and were even its officers.
One of the main supporters of the Fascist-Vatican pact was Mgr. E. Pacelli (the future Pope Pius XII), then in Germany. His brother, a lawyer, became one of the chief secret negotiators. He is seen in this photograph standing behind Cardinal …… Later, the Papal Nuncio to Germany, Mgr. E. Pacelli saw to it that his brother was made a Prince.