The Vatican on Monday allowed access for the first time to millions of diplomatic letters, private correspondence and other documents in its secret archives spanning the 1922-1939 papacy of Pius XI, which could provide insight into just how concerned the Holy See was by the growing persecution of Jews in Europe.
For years, the Vatican has struggled to defend Pius' successor the wartime Pope Pius XII, who had also served as a Vatican diplomat in Germany and later as Pius XI's secretary of state against claims he did not do enough to save Jews from the Holocaust.
Researchers said it could take months or years to study the contents of some 30,000 bundles of documentation from a period when fascism, nazism, communism and nationalism gripped much of the European continent.
Archives officials said that by late morning some 50 researchers had shown their credentials to gain admittance, although some of the scholars came to consult material on earlier papacies.
"There was a bit of chaos," said Alessandro Visani, a researcher in contemporary history at Rome's La Sapienza university who, like many others, was hoping for an initial idea of what was in the files, reports AP.
"I wanted to look at something but someone was already consulting it," said Visani, whose research includes the attitudes of church hierarchy toward the 1938 anti-Jewish laws of Italian fascist dictator Benito Mussolini.
One tantalizing question revolves around an encyclical Pius XI commissioned to denounce racism and the violent nationalism of Germany. But he died before releasing it, and it has never been made public.
The encyclical was never published "in part because of his death and in part because it was judged to be inopportune politically," Visani said.