When Europeans first encountered the highly developed monarchies of East Africa's interlacustrine region in the mid-nineteenth century, they accounted for them by inventing a theory of external causation: the hypothesis of prehistoric invasions by Asiatic "Hamites." In what later became Rwanda and Burundi, missionaries and colonial officials based their system of rule on this theory, bequeathing to postindependence regimes a poisonous ideology of ethnic differentiation. The first half of this scholarly history describes the interrelated precolonial kingdoms of Uganda, northwest Tanzania, and the eastern Congo as well as Rwanda and Burundi, and reviews the archeological, linguistic, environmental, oral, and written sources that refute the Hamitic hypothesis. The second part races through a hundred years of colonial and postcolonial history to depict colonialism's violent legacy, particularly in Rwanda. Although Chretien's argument is not easily accessible to a general audience, determined readers with some background will find a feast of information and analysis that confirms the author's assertion that the region has become a "laboratory" for reflecting on the writing of history.