Papal Nuncio (Ambassador) in Istanbul, Turkey, 1943-45
Archbishop Roncalli, who later became Pope John XXIII, interceded with King Boris of Bulgaria on behalf of the Bulgarian Jews, and with the Turkish government on behalf of Jewish refugees who had fled to Turkey. He also did his utmost to prevent the deportation of Greek Jews. One of the main sources of information to the Vatican about the Holocaust was provided by Roncalli. He provided reports about the annihilation of millions of Jews in Poland and Eastern Europe.