Ruanda-Urundi was a Belgian League of Nations Mandate and then UN trust territory from 1924 to 1962 when it became the independent states of Rwanda and Burundi.

The independent Kingdoms of Rwanda and Burundi were annexed by Germany along with the other states of the Great Lakes region in the late nineteenth and early twentieth century. A part of German East Africa the region had only a minimal German presence.

In the First World War the area was conquered by forces from the Belgian Congo in 1916. The Treaty of Versailles divided German East Africa with the vast majority known as Tanganyika going to Great Britain but the westernmost portion to Belgium, this area was formally referred to as the Belgian Occupied East African Territories. In 1924 they became Ruanda-Urundi when the League of Nations issued a formal mandate that granted Belgium full control over the area.

The Belgians were far more involved in the territory than the Germans, especially in Rwanda. Despite the mandate rules that the Belgians had to develop the territories and prepare them for independence the raubwirtschaft practiced in the Belgian Congo was exported eastwards. The Belgians demanded that the territories warn profits for the motherland and any development had to come out of funds gathered in the territory. These funds mostly came from the extensive cultivation of coffee in the regions rich volcanic soils. The populace was also extensively taxed and forced to perform corvée labour.

To implement their vision the Belgians used the indigenous power structure. This consisted of a largely Tutsi ruling class controlling a mostly Hutu population. The Belgian administrators were strong believers in the racial theories of the time and convinced themselves that the Tutsi were racially superior. While before colonization the Hutu had played an extensive role in governance the Belgians simplified matters by stratifying the society on racial lines. The anger at the oppression and misrule among the population was largely focused on the Tutsi elite rather than the distant colonial power. These divisions would play an important role in the decades after independence.

After the League of Nations was dissolved the region became a United Nations trust territory in 1946. This included the promise that the Belgians would prepare the areas for independence, but the Belgians felt the area would take many decades to ready for self rule.

Independence came largely as a result of actions elsewhere. In the 1950s an independence movement arose in the Belgian Congo, and the Belgians became convinced they could no longer control the territory. In 1960 Ruanda-Urundi's larger neighbour gained its independence. After two more years of hurried preparations the colony became independent on July 1, 1962, broken up along traditional lines as the independent nations of Rwanda and Burundi. It took two more years before the government of the two became wholly separate.

See also:

• History of Burundi
• History of Rwanda