While the Vatican this week has been dealing with the controversy surrounding Pope Benedict's comments on Islam, it also is bracing for another potentially divisive issue: Nazi's, Jews and the Catholic Church during World War II.
This week, the keepers of the secret archives, acting on orders from the late John Paul II, opened files covering a 17-year period preceding the war.
It is a part of history that precedes one of the most pivotal and destructive events of modern times.
There is an inarguable truth about the archives that rests deep within the Vatican's walls.
Whatever secrets they hold, they may never fully be revealed.
They are, in fact, called, the "Secret Vatican Archives."
There are millions of documents in the secret archives, housed in shelves that stretch for 50 miles.
The scale of the period boggles the mind, covering the life and times of the Catholic Church and its popes for the last 2,000 years.
The Vatican guards its secrets closely. From time to time, though, the archives are opened -- not to the public, but to historians and scholars.
The years 1922-1939 saw the rise of four infamous dictators: Spain's Francisco Franco, Benito Mussolini in Italy, Russia's Joseph Stalin, and in Germany, Adolph Hitler.
Of great interest to historians are the files related to Nazi Germany.
They have waited years for this opportunity so there was a brisk shuffling of scholarly feet when the archive doors swung open the first day.
Archivist Luca Carboni said to ABC News that he noticed right away a big difference from the previous week: "All the scholars who came this week are contemporary historians, usually we have medieval historians."
Researcher Alessandro Visani told The Associated Press that "there was a bit of chaos."
Visani, like his colleagues, was eager to get a first look at what was in the files.
"I wanted to look at something, but someone was already consulting it," he said.
The years now open for scrutiny cover the papacy of Pius XI.
Researchers will be looking for clues that will help shed light on the Vatican's attitudes toward what was happening to Jews in Nazi Germany and in Mussolini's fascist Italy.
Historians also hope the archives will provide more details about the pope who followed Pius XI.
That man is Cardinal Eugenio Pacelli. He went on to become Pope Pius XII during the war years.
During the reign of Pius XI in the years leading up to the war, Pacelli held two key posts.
He served as the Vatican's ambassador to Germany. He was later appointed secretary of state. He became pope just before the war broke out.
Critics of the wartime pope say that he did not do enough to save the Jews of Europe from the Holocaust.
The Vatican has always been adamant that Pius XII used quiet persuasion and back channels to save the lives of thousands of Jews.
Some historians, however, say that it's unlikely that any startling revelations will come out.
They point to the fact that in 2003 the Vatican released documents from key papal nuncios in Munich, Germany, and Berlin for the years covering the reign of Pius XI.
Still, the Rev. Giovanni Sale at the Jesuit magazine Civita Cattolica said to AP television that the archives would provide "a new beginning for a history without prejudice."
There is one thing researchers do agree on: that it will take time.
With 30,000 large bundles of documents to go through, some say it could take months, even years, to squeeze out any secrets.