Thirty years ago, an event of unprecedented and historic horror took place in East Africa: the genocide of Tutsis and the massacre of moderate Hutus. This event, which was covered in the media, amazed the whole world. Barbarity on an industrial scale caused the death of 800,000 to 1,000,000 people in 3 short months. The anniversary is an opportunity to review the causes and consequences of this massacre for Rwanda and the entire region. We publish this analysis in five parts, from the pre-colonization period to the current situation, including colonization, decolonization and the genocide period itself. It was first published in 2019 as a pamphlet.