While the matter remains one of debate, many contend that history’s first concentration camps were built in South Africa, 41 years before the Holocaust began.

These camps were built by British soldiers amid the Boer War, during which the British rounded up Dutch Boers and native South Africans and locked them into cramped camps where they died off by the thousands.

This is where the word “concentration camp” was first used – in British camps that systematically imprisoned more than 115,000 people and saw at least 25,000 of them killed off. In fact, more men, women, and children died of starvation and disease in these camps than did men actually fighting in the Second Boer War of 1899 to 1902, a territorial struggle in South Africa.

It was a horror that the world had never seen anywhere outside of the Bible. As one woman put it, “Since Old Testament days was ever a whole nation carried captive?”

And yet the first genocide of the 20th century started with good intentions. The camps were originally set up as refugee camps, meant to house the families that had been forced to abandon their homes to escape the ravages of war.

As the Boer War raged on, however, the British became more brutal. They introduced a “scorched earth” policy. Ever Boer farm was burned to the ground, every field salted, and every well poisoned. The men were shipped out of the country to keep them from fighting, but their wives and their children were forced into the camps, which were quickly become overcrowded and understocked.

The native South Africans, too, were sent to the camps. Some had their villages circled with barbed wire, while others were dragged off into camps, where they’d be forced to work as laborers for the British army and kept from giving food to the Boers.

Soon, there were more than 100 concentration camps across South Africa, imprisoning more than 100,000 people. The nurses there didn’t have the resources to deal with the numbers. They could barely feed them. The camps were filthy and overrun with disease, and the people inside started to die off in droves.

The children suffered the most. Of the 28,000 Boers that died, 22,000 were children. They were left to starve, especially if their fathers were still fighting the British in the Boer War. With so few rations to pass around, the children of fighters were deliberately starved and left to die.

The world became aware when a woman named Emily Hobhouse visited the camps and sent a report back home to England on the horrors she’d witnessed. “To keep these Camps going,” she wrote, “is murder to the children.”

As the war drew to a close, the British government tried to improve the camps – but it was already too late. The children there were already diseased and starving.

One worker, trying to curb the death rate in the camps wrote home: “The theory that, all the weakly children being dead, the rate would fall off is not so far borne out by the facts. The strong ones must be dying now and they will all be dead by the spring of 1903.”

By the end of the Boer War, an estimated 46,370 civilians were dead – most of them children. It was the first time in the 20th century that a whole nation was systematically rounded up, imprisoned, and exterminated.

But nothing tells the story as well as the photographs. In Emily Hobhouse’s words: “I can’t describe what it is to see these children lying about in a state of collapse. It’s just exactly like faded flowers thrown away. And one has to stand and look on at such misery, and be able to do almost nothing.”