No , the UK didn't invent the concentration camp. Only 32 British lost their lives against roughly 12.000 Mau Mau fighters and supporters.

The Mau Mau or Kenya Land and Freedom Army were defeated in 1960.

Makanga was just one of the estimated 150,000 Kenyans held in British prison camps for up to seven years during what was known as the Kenya Emergency, a rebellion against colonial rule in Kenya. Yes, British and commonwealth forces used concentration camps during the Boer War, and to a lesser extent the Mau Mau uprising in Kenya. Way more Kenyans were dead after the war. That dubious award goes to Spain in Cuba, though the US used similar camps in the early 19th century with native Indians.