Pope Pius XII (Eugenio Pacelli, 1876–1958) reigned as Pope from 1939 to 1958. He appears in UAP discourse via david-grusch’s 2023 congressional testimony, which alleged that Pius XII knew of a 1933 UFO crash near Milan and backchanneled information about the recovered craft to the U.S. government, which took possession after WWII.
The claim is unverified and remains a contested element of crash-retrieval-programs lore. It is rehearsed in the-age-of-disclosure (2025) and revisited in OSV News coverage of sam-sorich’s in-progress Catholic UAP documentary.