Ruanda-Urundi was a part of German East Africa under Belgian military occupation from 1916 to 1924 in the aftermath of World War I, when a military expedition had removed the Germans from the colony. It became a League of Nations Class B mandate allotted to Belgium, from 1924 to 1945. It was designated as a United Nations trust territory, still under Belgian administration, until 1962, when it developed into the independent states of Rwanda and Burundi. After Belgium began administering the colony, it generally maintained the policies established by the Germans, including indirect rule via local Tutsi rulers, and a policy of ethnic identity cards (later retained in the Republic of Rwanda). Revolts and violence against Tutsi, known as the Rwandan Revolution, occurred in the events leading to independence.
