Charles Boxer’s short book Race Relations in the Portuguese Colonial Empire 1415–1825 was published half a century ago and has continued to be read to this day. In fact, it constitutes a singular piece of analytical debate in the work of a writer who saw himself chiefly as a descriptive historian, bibliophile and archivist and who studiously avoided political posturing. The 1963 essay, however, was conceived from the start in a polemical mode, Boxer was perfectly conscious of the impact it would have as he produced it. The present essay is an assessment of the work in the light of the recent debates about racial differentiation and its implications in diverse historical and cultural contexts. The essay argues for the need to triangulate the traditional comparison between Brazil and the United States with the South African experience.