The first use of concentration camps in the twentieth century was during the 1899-1902
South African war (also known as the second Anglo-Boer War or just the
Boer War). After a series of defeats the Boer forces adopted
guerilla tactics early in 1900, splitting into small, relatively independent
commando forces which were supplied by friendly farms ("boer" is the
Afrikaans word for "farmer").
British commander-in-chief
Lord Kitchener accordingly adopted a kind of
scorched earth policy, burning around 30,000 farms and farmhouses, killing animals and interning women, children and farmworkers in camps around the country. There were 31 camps for Boer women and children and 65 for black workers and their families. Conditions in the camps were appalling -- especially so for those whose husbands and fathers were known still to be fighting, who were put on half rations.
Overcrowding,
malnutrition and inadequate medical care eventually killed many thousands of people: up to 27,000 Boer women and children and 20,000 black people, 80% of them children. (To put that in perspective, the joint forces of the two Boer
republics numbered just 35,000 at the start of the war.)
Although largely forgotten by the rest of the world, the memory of the concentration camps has scarred South Africa deeply. Through most of the twentieth century many Afrikaners carried a sense of bitter enmity for the British and all they stood for, branding them barbarous cowards and worse. The memory reinforced the Afrikaners' sense of isolation and vulnerability; one cannot properly understand apartheid without it.
The history of the black concentration camps has been almost completely ignored, even in South Africa, until very recently; archaeological evidence and oral history projects are now, belatedly, starting to fill the gap.