In this article, we explore the possibility that Marx had a far more complex understanding of the colonialization of Ireland than can be accounted for by Dependency theory. This insight is provided by an examination of Marx’s 1867 Report of the Irish situation during the height of Fenian activity in Britain. We propose that Marx’s crucial conceptualization in this theoretical work is to see colonialism as a regime, which originates at the political level within its various institutions and that the character of this regime changes over time. Accordingly, Marx systematically explores the evolution of the colonizing regime from the Plantations to the middle of the nineteenth century. However, Marx also explicates how the process of co...