Persecutions of the Catholic Church and Pius XII
Persecutions against the Catholic Church took place during the papacy of Pope Pius XII (1939–1958). Pius' reign coincided with World War II (1939–1945), followed by the commencement of the Cold War and the accelerating European decolonisation.
Source: Wikipedia — Persecutions of the Catholic Church and Pius XII (CC BY-SA 4.0)