>>513819426
Germans literally burned down like 80% of the contents of Polish archives in Warsaw with the oldest books and manuscripts going back to medieval times...

>During the German suppression of the Warsaw Uprising of 1944, around 70 to 80% of libraries were carefully burned by the Brandkommandos (burning detachments), whose mission was to burn Warsaw.[13] In October 1944 the Załuski Library, the oldest public library in Poland and one of the oldest and most important libraries in Europe (established in 1747), was burned down.[14] Out of about 400,000 printed items, maps and manuscripts, only some 1,800 manuscripts and 30,000 printed materials survived.[14]

>In the last phase of the Warsaw Uprising and after its collapse, in September and October 1944, the three major private libraries in Warsaw (Krasiński Library, Przeździecki Library and the Library of Zamoyski Family Entail), including collections of priceless value to Polish culture, ceased to exist.[15] Those libraries had already suffered in September 1939, when they were bombed and burned.[15]

https://en.wikipedia.org/wiki/Destruction_of_Warsaw#Burning_of_libraries