In this article I demonstrate the utility of an historical study of social change by examining the development of political authority on the Peruvian north coast during the Moche period through its symbols of power. We too often equate the material record with “archaeological culture,” assume that it reflects broad cultural reality, and interpret it by reference to general evolutionary models. Here I reassess Moche society within its historic context by examining the relationship between underlying social structure and short-term processes that shaped Moche political formation, and reach very different conclusions. I see the “diagnostic” Moche material record primarily as the symbolic manifestation of a distinctive political ideology whose character was historically constituted in an ongoing cultural tradition. Aspiring rulers used ideology to manipulate cultural principles in their interests and thus mediate the paradox between exclusive power and holistic Andean social structure which created the dynamic for change. A historic study allows us to identify the symbolic and ritual mechanisms that socially constituted Moche ideology, and reveals a pattern of diversity in time and space that was the product of differential choice by local rulers, a pattern that cannot be seen within a theoretical approach that emphasizes general evolutionary or materialist factors.