When the Kingdom of Rwanda formed in the 15th century, there were two groups divided by both ethnicity and class. The Hutus were primarily (but not completely) a peasant class that provided agricultural labor, and the Tutsis were a class of warriors that included the kingdom’s rulers and much of its nobility. Generally, Tutsis ruled over the Hutus in a system much like feudalism in medieval Europe, with new people conquered by the Kingdom of Rwanda usually considered Hutus. After Germany colonized Rwanda at the end of the 19th century, with Belgium later taking control over Rwanda in 1916, the monarchy and social structure of Rwanda were largely left intact. In fact, the Belgian rulers of Rwanda supported the existing monarchy and favored the Tutsis, in order to help them preserve their own domination over the country. Under Belgian influence, Rwanda became a devoutly Catholic country where French was spoken along with the native Bantu languages of Kinyarwanda and Swahili.

As anti-colonial movements spread across Africa following World War II, Hutu resistance grew. The Tutsis became associated with oppression under European colonial rule. Also, the Catholic Church in Rwanda became staunch supporters of the Hutu cause.