Because of its high population—estimated to be 107 million people—and the agricultural surplus in the region, the area became organized into a number of small states. The most powerful of these monarchies were Buganda, Bunyoro, Rwanda, and Burundi. Unusual for sub-Saharan Africa, the traditional borders were largely maintained by the colonial powers, however the national borders were often drawn to divide monarchies that the colonials did not favor or to keep preferred groups in relative dominance over groups perceived as less euro-centric.