Born Eugenio Pacelli, he was elected Pope in 1939. During the war he organized a vast program of humanitarian aide in favor of Jews and opponents of totalitarian regimes. Once the war was over his pastoral activity was taken up with with the fight against Marxism. By his order excavations under St Peter's were undertaken, and the tomb of St Peter was found.

He proclaimed the dogma of the bodily assumption of the Virgin Mary (1950) and in 1951 restated the doctrine (strongly criticized by Protestants and many Catholics) that the life of an infant must not be sacrificed to save a mother in labour.

There are rumors about him having been gay.