Using primary sources (oral tradition, archival materials, archaeological evidence, 19th century European explorers’ and missionaries’ accounts) and secondary sources (historical, anthropological, archaeological, etc.), this article reevaluates, in a historical perspective, the decline and diminishment in political power and scale as well as in population and landmass of Bunyoro-Kitara, the earliest kingdom in East Africa’s lake region. It concludes that, contrary to the conventional wisdom proffered by 19th century Europeans and sanctified by Makerere University scholarship, the kingdom declined essentially because of the extraordinary errors of judgment and incompetence of most of its rulers from the close of the 17th century to the close of the 19th century, devastating deceases (human and animal), and brutal British conquest resulting in the death of thousands of individuals and loss of territory. By 1900 the kingdom’s population had declined by about four-fifths and landmass by about two-thirds. No major African kingdom experienced such an enormous outcome. Herein lies the fascination with this subject.