ROME — A letter discovered in the Vatican archives by archivist Giovanni Coco reveals that a German Jesuit priest active in the anti-Nazi resistance reported to Pope Pius XII’s personal secretary that about 6,000 people, especially Poles and Jews, were being killed daily at the Belzec extermination camp in occupied Poland during World War II.
Coco described the find as “a unique case” with “tremendous value.” The letter, dated Dec. 14, 1942, was written by German Jesuit Father Lothar König, based near Munich, to German Jesuit Father Robert Leiber, a key and trusted adviser of Pope Pius XII for decades — from the future pope’s time as papal nuncio in Munich, through his tenure as Vatican secretary of state, and throughout his pontificate from 1939 to 1958. The Belzec extermination camp had started its operations in March 1942.
The letter also made reference to the camp at Auschwitz and an indirect reference to Dachau. Journalist Massimo Franco, who interviewed Coco for the Italian newspaper Corriere della Sera, said the discovery “makes it clear that in reality much more detailed reports about the extermination underway were getting to the Vatican.” Franco noted the letter likely belonged to a larger correspondence between the two priests, though the other letters have not been found — “perhaps they were destroyed or lost,” he said.
“These are some hints that make it clear the so-called ‘Final Solution’ had already not just begun in 1942, but in some way it is a clear reflection that it was getting (reported) to the Vatican and the pope himself,” Franco said. The letter is “also important because it makes it clear how much pressure the Nazis were putting on Pope Pius XII and, therefore, how terrorized the Catholic Church in Germany and Poland were that any kind of disclosure could in some way worsen Nazi retaliation against Catholics and Jews,” he added.
It is strongly believed the pope received the news in the letter. Just 10 days after its date, on Christmas Eve 1942, Pope Pius XII issued a strongly worded appeal denouncing the fact that hundreds of thousands of people were being “marked down for death or gradual extinction,” sometimes only by reason of their race — though he did not explicitly mention the Nazis or Jews by name.
The letter had been registered in the archive only in 2019 and was described as “a bit ruined.” In 2022, German historian Michael Feldkamp offered separate evidence from the Vatican archives that Pius XII knew early on about the Holocaust and sent a message to U.S. President Franklin D. Roosevelt in March 1942 regarding “the systematic extermination of European Jews.” Feldkamp said “these messages were not considered credible by the Americans” but noted that Roosevelt’s associates in the State Department “repeatedly contacted Pius XII for information on individual cases.”
“Today we know … that Pius XII was confronted with the persecution of the Jews almost on a daily basis,” Feldkamp told Vatican News. He estimated that “Pius XII personally saved about 15,000 Jews through his own personal efforts: opening monasteries, raising cloisters so that people could be hidden there, and so on.” Further discoveries in the Vatican’s archives on the pontificate of Pius XII are expected to add to the historical record of what the pope knew, what he did, and why he did not publicly condemn the atrocities by name.