On February 10, 1939, Pope Pius XI passed away, making way for the election of his successor. In his last days, he expressed concern over the potential impact of his death, especially mentioning Cardinal Pacelli, whom he deemed irreplaceable. Pius XI's foresight illustrated the challenges ahead for the Catholic Church, emphasizing the importance of stable leadership during tumultuous times.

The conclave convened on March 2, 1939, and ultimately chose Cardinal Eugenio Maria Giuseppe Giovanni Pacelli, who assumed the papacy just ten days after Pius XI's death. Prior to his election, Pacelli held significant positions, notably that of Secretary of State, essentially the Vatican's equivalent to a prime minister, which positioned him well to navigate the upcoming global conflicts. His leadership would soon be tested as World War II loomed on the horizon.

Pope Pius XII's election came at a crucial point in history, marked by rising tensions in Europe and the signing of the Reichskonkordat in 1933, which was a controversial treaty between the Holy See and Nazi Germany. As the new pope, Pius XII was tasked with guiding the Church through these complex political landscapes, balancing spiritual authority while navigating the potential moral implications of the violent global realities that were about to unfold.