English actor Leo Genn was a surprise choice to lead No. 1 War Crimes Investigation Team at Bergen-Belsen concentration camp – the first camp to be liberated by British troops. He was aided by Major Savile Champion, a solicitor in the Royal Artillery.

‘The crimes they were hearing about [at Belsen] were far outside their experience, anyone’s experience,’ Andrew Williams, a law professor at the University of Warwick, observes in this excellent book.

The Belsen team felt they were ‘operating in a legal void’ as it was unclear whether SS men and women in custody would be accused of ‘neglect’, ‘mass murder’, or ‘gross cruelty’. When formal authority to prosecute the alleged Nazi war criminals came in the form of a royal warrant, Genn, Champion and Yorkshire solicitor Major Noel Till, of No. 2 War Crimes Investigation Team at Sandbostel prisoner of war camp, were told that military courts would hear violations of the laws of war committed after the outbreak of war.

Williams’ book marks the 70th anniversary of the Nuremberg trials, but what makes it distinctive is its insightful treatment of the 1945 Belsen trial – the only British or American trial that directly examined individual deeds at Auschwitz.

Although hundreds of witnesses at Belsen had given statements to British investigators, keeping track of their movements was a challenge; after all, ‘who would want to stay in that hell-hole?’, writes Williams. For ‘the fair-minded British lawyers’ proving personal responsibility was crucial, contrasting sharply with US Justice Jackson’s ‘premise that membership of the SS and other criminal organisations would be enough to establish guilt’.

In reading through the Belsen trial papers, Williams concludes that ‘caution had infected the prosecution lawyers’ work’ and perhaps they chose a ‘restrained terminology of wrongdoing’ so that the defendants ‘would have less chance to raise a reasonable doubt concerning their guilt’. As for the 42 accused (including ‘Beast of Belsen’ Josef Kramer, pictured), represented by 12 lawyers who were all British officers, their defence was based ‘on the supposed “German” culture and law of blind obedience to excuse everyone on trial’.

Williams considers Deputy Judge advocate Carl Stirling’s summing-up to the military panel which would decide on the guilt of the accused. He noted: ‘That the prosecution must prove the guilt of the prisoner is part of the common law of England, and no attempt to whittle it down can be entertained’. Williams concludes: ‘For good or ill, British justice applied with little regard to the extraordinary context’.

Turning to the International Military Tribunal at Nuremberg, Williams describes how a film showing the liberation of the camps was shown to the court, ‘making redundant the efforts of prosecutors to describe and understand the conditions found in those places’. Having watched the film several times, Williams concludes that it didn’t establish ‘the slightest connection between defendants and these crimes’, though perhaps its purpose was to provide a ‘visual reignition of the initial outrage’.

Away from the courtrooms, Williams offers a nightmare travelogue. At Bergen-Belsen he recoils at the thought of having a snack in the cafeteria in the modern exhibition building. Here prisoners were ‘driven mad enough to claw the soil for any scrap of edible matter’. At Buchenwald, Williams is appalled that animals in the zoo were properly looked after, ‘mocking the human beings inside the camp’.

Williams’ history inevitably becomes an impersonal account as Allied investigators slowly uncover the scale of the Holocaust. As he concedes: ‘For all Nuremberg’s value in confronting the overarching systems of Nazi inhumanity, the victims were only numbers.’

Nicholas Goodman is a sub-editor at the Gazette