Hutu and 14% of residents in Rwanda and Burundi, respectively. The Twa pygmies, the smallest of the two countries' principal populations, also share language and culture with the Hutu and Tutsi. However, they are distinguished by a considerably shorter stature. The Hutu are believed to have first emigrated to the Great Lake region from West Africa in the great Bantu expansion. Various theories have emerged to explain the purported physical differences between them and their fellow Bantu-speaking neighbors, the Tutsi. One such thesis, largely based on oral tradition, posits that the Tutsi experienced some admixture with or were partially descended from
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