Letter between Pope Pius XII, who served as Pope during World War II, and a German Jesuit reveals Pius knew of the atrocities committed by the Nazis during the Holocaust
- Correspondence between Pope Pius XII, who served as Pope during World War II, and a German Jesuit, has shed light on Pius’s awareness of the Nazi atrocities
- Revelation was reported in an article in Italy published earlier this week and states how Pius had received information about the daily gassing of 6,000 Jews
- The revelation undermines the Holy See’s previous argument it couldn’t confirm official reports of atrocities, thus hindering its ability to denounce them
Wartime Pope Pius XII knew details about the Nazi attempt to exterminate Jews in the Holocaust as early as 1942, according to a letter found in the Vatican archives.
The correspondence suggests Pius XII had detailed information from a trusted German Jesuit that up to 6,000 Jews and Poles were being gassed each day in German-occupied Poland.
The details in the letter conflict with the Holy See’s official position at the time that the information it had about the mass murder of Jews was vague and unverified.
The yellowed, typewritten letter, reproduced in Italy‘s Corriere della Sera on Sunday, is highly significant because it was discovered by an in-house Vatican archivist and made public with the encouragement of Holy See officials.
The letter, dated December 14, 1942, was written by Father Lother Koenig, a Jesuit who was in the anti-Nazi resistance in Germany, and addressed to the pope’s personal secretary at the Vatican, Father Robert Leiber, also a German.
Vatican archivist Giovanni Coco told the Corriere that the importance of the letter was ‘enormous, a unique case’ because it showed the Vatican had information that labor camps were actually death factories.





Coco said the letter was significant because it represented detailed correspondence about the Nazi extermination of Jews, including in ovens, from an informed church source in Germany who was part of the Catholic anti-Hitler resistance that was able to get otherwise secret information to the Vatican.
Coco said Koenig’s letter actually was found in the Vatican’s secretariat of state archives and was turned over to the Vatican’s main Apostolic Archives in 2019.
The secretariat of state’s papers were disorganized and scattered, with some of Pius’ documents kept in plastic containers in an attic storage space where heat and humidity were damaging them.
It could mark the first time a reference to Jews being gassed in ovens had been revealed in a letter that would certainly have been brought to Pius’ attention.
In the letter, Koenig tells Leiber that sources confirmed about 6,000 Poles and Jews a day were being killed in ‘SS-furnaces’ at the Belzec camp near Rava-Ruska, which was then part of German-occupied Poland and is now in western Ukraine.
‘The newness and importance of this document derives from a fact: now we have the certainty that the Catholic Church in Germany sent Pius XII exact and detailed news about the crimes that were being perpetrated against the Jews,’ Coco told the newspaper, whose article was headlined: ‘Pius XII Knew’.
Asked by the Corriere interviewer if the letter showed that Pius knew, Coco said: ‘Yes, and not only from then.’
The letter made reference to two other Nazi camps – Auschwitz and Dachau – and suggested there were other missives between Koenig and Leiber that either have gone missing or have not yet been found.




According to the Belzec camp memorial which opened in 2004, a total of 500,000 Jews perished at the site.
The memorialĀ“s website reports as many as 3,500 Jews from Rava Ruska had already been sent to Belzec earlier in 1942 and that from December 7-11, the city’s Jewish ghetto was liquidated.
‘About 3,000-5,000 people were shot on the spot and 2,000- 5,000 people were taken to Belzec,’ the website says.
The date of Koenig’s letter is significant because it suggests the correspondence from a trusted fellow Jesuit arrived in Pius’ office in the days after the ghetto was emptied, and after Pius had received multiple diplomatic notes and visits from a variety of envoys of foreign governments from August 1942 onwards with reports that up to 1million Jews had been killed so far in Poland.
While it can’t be certain that Pius saw the letter, Leiber was Pius’ top aide and had served the pope when he was the Vatican’s ambassador to Germany during the 1920s, suggesting a close working relationship especially concerning matters related to Germany.



Supporters of Pius say he worked behind the scenes to help Jews and did not speak out in order to prevent worsening the situation for Catholics in Nazi-occupied Europe.
His detractors say he lacked the courage to speak out on information he had despite pleas from Allied powers fighting Germany.
The letter was among documents Coco said were kept in haphazard ways in the Vatican’s Secretariat of State and only recently handed over to the central archives where he works.
The historic moment was preceded by decades of controversy and debate about why the pontiff, who headed the Catholic Church from 1939 until his death in 1958, never spoke out about the slaughter of 6million Jews in Nazi concentration camps across Europe.
Kept confined to the Vatican by the Nazis and then Italian Fascists, Pius XII was a German-speaking Italian aristocrat who witnessed Hitler’s rise while posted as the Holy See’s ambassador in Germany for 12 years.



The archives give historians a chance to better understand Pius XII’s reticence, which some view as unforgivable.
Others note the Church still saved around 4,000 Jews from certain death by hiding them in its Roman institutions – and he had to stay neutral to better shield Catholics from the unfolding devastation.
The Vatican usually waits 70 years after the end of a pontificate to open archives but it had been under pressure to make the Pius XII documentation available sooner, while Holocaust survivors are still alive.
‘The Church is not afraid of history,’ Pope Francis declared when he chose to open one of the Vatican’s most painful moments up for world scrutiny in 2019.
The Vatican first published the essentials covering the Holocaust four decades ago, an 11-volume work compiled by four Jesuit priests.
But some crucial pieces are still missing, such as the pope’s replies to notes and letters – including those about the Nazi horrors.
The unsealed archives additionally cover a post-World War II era in which writers were censored and some priests hounded for suspected communist sympathies.
The Vatican has long defended Pius, sometimes derided as ‘Hitler’s Pope’ because of his reluctance to condemn Nazi war crimes, saying he used behind-the-scenes diplomacy to try to save lives.


Pius XII ‘never raised his voice and I doubt that these documents will contradict this,’ said Italian historian Anna Foa, characterizing his style as ‘very diplomatic and traditional.’
‘During the war, he thought his duty was to save lives but not to condemn ideologies,’ said Foa.
‘Pius XII was a product of his time. He was not particularly anti-Jewish, but he refused to disavow the anti-Jewish history of the Church.’
Suzanne Brown-Fleming, director of International Academic Programs at the U.S. Holocaust Memorial Museum in Washington DC, said the release showed that the Vatican was taking seriously Pope Francis’ statement that ‘the Church is not afraid of history’ when he ordered the wartime archives opened in 2019.
‘There is both a desire for and support for a careful assessment of the documents from a scientific perspective – whether favorable or unfavorable in what the documents reveal,’ she said.
Researchers have long sought to examine the archives over why Pius XII did not intervene more against the Holocaust perpetrated by the German Nazis, an attitude denounced as a form of passive complicity.
A 1999 work by British journalist John Cromwell accused Pius of doing too little to speak up for Hitler’s victims during the war, and a failure to explain himself afterwards.
His work, Hitler’s Pope, claimed that Pius was anti-Semitic, citing this alleged prejudice as a reason for staying quiet. The allegations were strenuously denied by the Vatican.
Pius’ supporters have long insisted that he couldn’t speak out strongly against the Nazis because of fears of reprisals.
David Kertzer, Pulitzer Prize-winning author of ‘The Pope at War’, a 2022 book about the Pius years, said Coco was a ‘top notch, serious scholar’, centrally placed in the Vatican to unearth the truth.
Brown-Fleming, Coco and Kertzer will be part of a major conference on Pius and the Holocaust next month at the Pontifical Gregorian sponsored by Catholic and Jewish organizations, the U.S. State Department and Israeli and American Holocaust research groups, among others.