German soldier in Burundi during the WWI

The territories of Burundi, Ruanda and Tanzania were colonized by the German Empire from 1885 onwards. At the end of the First World War, some 1,000 German soldiers and their auxiliaries (indigenous soldiers integrated into the German army) were still undefeated, pursued by between 200,000 and 300,000 British, Belgian and Portuguese troops. Under the leadership of General Paul-Emil Von Lettow Vorbeck, the German troops in Africa obtained very favorable peace terms for their surrender.

This scorched-earth war indirectly cost the indigenous population many deaths from disease and starvation. According to some historians, up to 20% of the population of these regions may have died under these conditions.

After the war, Belgium took control of Ruanda-Urundi on behalf of the League of Nations following the First World War.