Ruanda-Urundi (), later Rwanda-Burundi, was a colonial territory, once part of German East Africa, which was occupied by troops from the Belgian Congo during the East African campaign in World War I and was administered by Belgium under military occupation from 1916 to 1922. It was subsequently awarded to Belgium as a Class-B Mandate under the League of Nations in 1922 and became a Trust Territory of the United Nations in the aftermath of World War II and the dissolution of the League. In 1962 Ruanda-Urundi became the two independent states of Rwanda and Burundi. History Ruanda and Urundi were two separate kingdoms in the Great Lakes region before the Scramble for Africa. In 1897, the German Empire established a presence in Rwanda with the formation of an alliance with the king, beginning the colonial era. They were administered as two districts of German East Africa. The two monarchies were retained as part of the German policy of indirect rule, with the Ruandan king (mwami) Yuhi V Musinga using German support to consolidate his control over subordinate chiefs in exchange for labour and resources. Belgian military occupation, 1916–1922 World War I broke out in 1914. German colonies were originally meant to preserve their neutrality as mandated in the Berlin Convention, but fighting soon broke out on the frontier between German East Africa and the Belgian Congo around Lakes Kivu and Tanganyika. As part of the Allied East African Campaign, Ruanda and Urundi were invaded by a Belgian force in 1916. German forces in the region were small and hugely outnumbered. Ruanda was occupied over April–May and Urundi in June 1916. By September, a large portion of German East Africa was under Belgian occupation reaching as far south as Kigoma and Karema and as far eastwards as Tabora all in modern-day Tanzania. In Ruanda and Urundi, the Belgians were welcomed by some civilians, who were opposed to the autocratic behaviour of the kings. In Urundi, much of the population fled or went into hiding, fearful of war. Much of the Swahili trader community which resided along the shores of Lake Tanganyika fled towards Kigoma, as they had long been commercial rivals with Belgian traders and feared retribution. The territory captured was administered by a Belgian military occupation authority ("Belgian Occupied East African Territories") pending an ultimate decision about its political future. An administration, headed by a Royal Commissioner, was established in