Hilberg served first in the 45th Infantry Division during World War II, but, given his native fluency and academic interests, he was soon attached to the "War Documentation Department", charged with examining archives throughout Europe. While quartered in the Braunes Haus, he stumbled upon Hitler's crated private library in Munich. This discovery, together with learning that 26 close members of his family had been exterminated, prompted Hilberg's research into the Holocaust, a term which he personally disliked, though in later years he himself used it. In a lecture he gave in Vienna some time before his death he went on record as saying,'We know perhaps 20 per cent about the Holocaust.