In the early 1930s, the Belgian colonial government in Rwanda implemented a census that assigned ethnic identities to the population, categorizing Rwandans as Hutu, Tutsi, or Twa. This system solidified their identities on official documents, effectively entrenching a rigid social structure that favored Tutsis, a minority group, over the majority Hutus. The identity cards created a formidable barrier, preventing Hutus from being recognized as Tutsis and reinforcing a system of apartheid based on a fabricated notion of Tutsi superiority.

The Belgians' actions transformed the understanding of ethnic identity in Rwanda, overshadowing any previous meanings that might have existed in the pre-colonial period. Instead of a society where identity was fluid or multifaceted, the imposed ethnic labels became the central aspect of Rwandans' lives, leading to deep social divisions and laying the groundwork for future conflicts. The colonial regime's focus on ethnicity fundamentally altered Rwandan society, making it a primary characteristic that dictated people's lives and interactions.