Rwandan monarchy and supporting Tutsi chiefs; this system allowed colonisation with few European troops. Yuhi V Musinga, who emerged as king after a succession crisis following the death of his father Rwabugiri and a struggle with Belgian troops, welcomed the Germans and used them to consolidate his power. The territory became the western border of German East Africa. German rule allowed Rwabugiri's centralisation policy to continue, and the rift between Tutsi and Hutu deepened. Belgian forces took control of Rwanda and Burundi during World War I, and the country came under Belgian control in a 1919 League of Nations mandate, named Ruanda-Urundi. Although Belgium initially continued the German method of government through the monarchy, in 1926, it began a policy of direct colonial rule in line with the norm in the Congo. Reforms included simplifying the complex three-chieftain system, so one chief (usually Tutsi) instead of three (typically split between Tutsi and Hutu) ruled a local area. Belgian reforms also extended uburetwa (forced labour by Hutus for Tutsi chiefs) to individuals, not just communities, and to regions not previously covered by the system. Tutsi chiefs began a process of land reform with Belgian support; grazing areas traditionally controlled by Hutu collectives were seized by Tutsi and privatised with minimal compensation. Beginning in the late 1920s, the role of the Catholic Church grew. This was encouraged by the Belgian government, since the priests knew the country well and facilitated its administration. Many Rwandans (including elite Tutsi) converted, since Catholicism was an increasing prerequisite for social advancement. King Musinga refused to convert, and in 1931 he was deposed by the Belgian administration; his eldest son, Mutara III Rudahigwa, succeeded him and eventually became Rwanda's first Christian king. During the 1930s the Belgians introduced large-scale projects in education, health, public works and agricultural supervision, including new crops and agricultural techniques to improve food supply. Though Rwanda was modernised the Tutsis remained in power, leaving the Hutu disenfranchised and subject to large-scale forced labour. In 1935 Belgium introduced identity cards, labelling an individual as Tutsi, Hutu, Twa or Naturalised. Although wealthy Hutu had previously been able to become honorary Tutsi, the identity cards ended further social mobility. Prelude Hutu counter-elite Belgium continued to rule Rwanda as a UN Trust Territory after World War II, with a mandate to oversee its eventual independence. The economic landscape had changed considerably during the war; a cash economy