In November 1923 Hitler had led an attempted coup against the Weimar Government by trying to seize power in the Bavarian city of Munich. The putsch failed and Hitler was found guilty of treason in the subsequent trial. Sentenced to five years imprisonment, he was sent to the Festungshaft prison in the Bavarian town of Landsberg am Lech.

Hitler’s ‘fortress confinement’ provided him with a reasonably comfortable cell in comparison to conventional facilities, and meant that he was able to receive mail and have regular visitors. The discovery in 2010 of more than 500 documents relating the Hitler’s imprisonment show ...