twin territory in central East Africa that was administered by Belgium from 1922 to 1962 and which thereafter became the independent states of Rwanda and Burundi (qq.v.). After World War I, in 1922, with an adjustment of frontiers, a slice of what had been formerly German East Africa came under Belgian control and, in 1924, became the mandate of Ruanda-Urundi, under League of Nations auspices. After World War II, in 1946, the twin territory was reconstituted as a United Nations trust territory. Throughout its history it was administered under a vice governor-general as an integral part of the Belgian Congo, but with a separate budget.