The origins between the ethnic tensions between the Tutsi and Hutus in Rwanda are found in the original waves of migration and later into the domination of the Kingdom of Rwanda formed by the Tutsi clans. The Kingdom of Rwanda became the framework used by the German colonials to exercise power. Although the economy was reformed following the transfer to Belgian rule after World War I, the Hutu majority remained disenfranchised. Socio-economic differences were further cemented in 1935, when the Belgians introduced identity cards with Hutu or Tutsi distinctions.
Relations deteriorated after World War Two when a Hutu elite formed, and in 1959, what began as attacks on Tutsi targets evolved into the Rwandan revolution. The Belgian colonials began a programme of promotion for Hutus and following elections in the mid-1960s, the Hutus took control of most constituencies. More than 336,000 Tutsis fled Rwanda during the revolution and a failed insurgency was launched in the late 1960s.
By the late 1980s, many former Tutsi refugees in Uganda had gained integral roles in the Ugandan National Army following the overthrow of Milton Obete by Yoweri Museveni. In 1990, a Tutsi faction within the Ugandan Army, the Rwandan Patriotic Front, led by Fred Rwigyema invaded Uganda. However, the RPF came in disarray following Rwigyema’s death on the second day of the attack. This led another Tutsi officer from the Ugandan Army, Paul Kagama, to step in. The troops were reassembled and another campaign was lauched in 1991. By 1992, the Arusha Accords were signed in Tanzania, providing for a power-sharing government. The war took a turn for the worst when on April 6, 1994, the plane of then-President Juvénal Habyarimana, a Hutu, was shot over Kigali killing everyone on board. The next day, the Rwandan Army, alongside civilians began killing Tutsi and moderate Hutu leaders, which marked the beginning of the 3-month long genocide of Tutsis in Rwanda, until the killing was ended in July 1994 when the RNF forced the interim government into exile. Approximately 2,000,000 Hutus also fled to the Democratic Republic of Congo, Burundi, Tanzania and Uganda.