In this thesis, the ways in which organised violence functioned as an economic power in two historical periods - Aztec and Conquest Mexico - are discussed. The fundamental socio- economic characteristics of the Aztec and Conquest social formations are outlined in materialist terms. This is followed by a discussion of the ways in which particular forms of organised violence functioned both to maintain a dominant class in a position of power in relation to subordinate classes, and to enforce a particular set of economic relations within the social formation which benefited this dominant class. The interconnections between specific forms of organised violence in Aztec and Conquest Mexico and the economic context in which they occurred are, therefore, illustrated. Through this approach, a sense or underlying coherence is brought to the discussion of organised violence in these two historical periods. Organised violence is discussed as part of the mechanics of a social formation, not as events separated from a social context.