In the 1960s "internal colonialism" became an important theory advanced to explain the historical development of ethnic and racial inequality in the modern world. By the 1980s the theory had been dismissed as inadequate. Nonetheless, its influence persisted as more global colonial theories evolved. This article argues that internal colonialism continues effectively to explain the historic subordination of indigenous peoples within larger states dominated by other groups. Furthermore, internal colonialism is applicable globally to dynastic and national states, as well as contiguous empires, from antiquity to the present-a breadth that attests to this theory's continuing significance.