 Pius XII issued 41 encyclicals during his pontificate — more than all his successors in the past 50 years taken together — along with many other writings and speeches . The pontificate of Pius XII was the first in Vatican history that published papal speeches and addresses in vernacular language on a systematic basis . Until then , papal documents were issued mainly in Latin in Acta <unk> Sedis since 1909 . Because of the novelty of it all , and a feared occupation of the Vatican by the German Wehrmacht , not all documents exist today . In 1944 , a number of papal documents were burned or " walled in " , to avoid detection by the advancing German army . Insisting that all publications must be reviewed by him on a prior basis to avoid any misunderstanding , several speeches by Pius XII , who did not find sufficient time , were never published or appeared only once issued in the Vatican daily , <unk> Romano . 
