In 1952, Bullock published Hitler: A Study in Tyranny, the first comprehensive biography of Adolf Hitler, which he based on the transcripts of the Nuremberg Trials.
When reviewing Hitler: A Study in Tyranny in The Times in 1991, John Campbell wrote "Although written so soon after the end of the war and despite a steady flow of fresh evidence and reinterpretation, it has not been surpassed in nearly 40 years: an astonishing achievement."[REF] .