Tutsi (largest) and the Twa (smallest). Small numbers of Hema, Kiga and Furiiru people also live near the Tutsi in Rwanda. The Northern Tutsi who reside in Rwanda are called Ruguru (Banyaruguru), while southern Tutsi that live in Burundi are known as Hima, the Tutsis who resides in Masisi which is in Kivu and they are known as Banyamasisi and the Tutsi that inhabit the Kivu plateau in the Congo go by Banyamulenge. The definitions of "Hutu" and "Tutsi" people may have changed through time and location. Social structures were not stable throughout Rwanda, even during colonial times under the Belgian
Tutsi after mid-1600. Beginning in about 1880, Roman Catholic missionaries arrived in the Great Lakes region. Later, when German forces occupied the area during World War I, the conflict and efforts for Catholic conversion became more pronounced. As the Tutsi resisted conversion, missionaries found success only among the Hutu. In an effort to reward conversion, the colonial government confiscated traditionally Tutsi land and reassigned it to Hutu tribes. In Burundi, meanwhile, Tutsi domination was even more entrenched. A ruling faction, the Ganwa, soon emerged from amongst the Tutsi and assumed effective control of the country's administration. The area was ruled as