Today, the expression “concentration camp” evokes the horrors of Nazi Germany, conjuring up black-and-white images of Auschwitz and Belsen. But Germans were neither the first nation to make use of concentration camps nor the last.

Both during and immediately after the war, concentration camps and slave-labor camps operated throughout the United Kingdom. A year after World War II’s end, British agriculture only functioned thanks to slave labor. In May 1946, while high-ranking SS officers were preparing for trial at Nuremberg, 385,000 enslaved workers were held behind barbed wire across the British Isles; thousands more were arriving every week. At the time, they made up over 25 percent of the land workforce.

The British had been early adopters of these exceedingly useful establishments. During the Second Boer War (1899–1902), they set up a network of camps in which conditions were so grim that over twenty-two thousand children under the age of sixteen died of starvation and disease.