Britain's National Archives on Friday made public a previously classified account of Hitler provided by a 19-year-old Austrian deserter, who described the dictator as paranoid about being watched by others and short-tempered during meetings.
"He is mild on personal contact but apt to bang tables and shout during conferences," according to the account given by a prisoner of war identified as SS Schuetze Obernigg. He was said to have been at Hitler's retreat in Obersalzberg in the Bavarian Alps between 1943 and 1944.
Obernigg provided British intelligence officers with a detailed description of Hitler's daily routine at the retreat. Hitler was said to favor waking up at about 10 a.m., breakfasted on coffee, bread and marmalade shortly afterward, and received visitors including his doctor in the afternoon. The accounts show he apparently worked until late in the night and went to sleep as late as 4 a.m.
The deserter also described Hitler's attitude toward his personal guards.
"Hitler cannot bear to feel himself watched ... guards were instructed to keep him in sight but to remain unobserved themselves," said Obernigg, according to the files.
A separate set of files also released by the National Archive Friday showed that Allied forces were deeply concerned about the possible existence of a secret Nazi hideout in the Austrian Alps where Hitler would make a "last desperate stand" after the end of World War II.
Intelligence reports from around 1944 to 1945 suggested that the so-called "Nazi National Redoubt" could hold enough food and weapons in underground caves for up to 60,000 "Nazi fanatics" for two years, according to files made public by Britain's National Archive.
The files contained detailed reports of the training and movement of troops as well as fuel and food in the Alpine area between western Austria and upper Bavaria. An intelligence summary described the mountain base as a place "in which the elite of National Germany will make a last desperate stand."
One report dated April 7, 1945, sourced from French intelligence for the Office of Strategic Services, the precursor to the CIA, said the Germans were planning to take 300,000 to 400,000 foreign prisoners to the hideout.
The documents suggest that the Allies were convinced about the Nazi mountain refuge - although historians say the base turned out to be a myth.
"There was every indication the Nazi regime would fight until the last man," said Mark Dunton, a contemporary history specialist at the National Archive.
"(The Allies) were sort of piecing together various observations about the movements of foodstuffs into this area, and a movement of weapons and gasoline, and they kind of ... put two and two together to make five," he said.