In this paper I outline a historical materialist framework for the transhistorical critique of ethnicity, providing a case study in the shaape of Armenian settlements in medieval New Rome. This is necessary since constructivism – the dominant theoretical tradition of the last forty years or so – has failed to dethrone common sense, methodologically nationalist assumptions over the ‘formation’ and ‘survival’ of apparently ‘constructed’ ethnic groups. The purpose is not to reject non-Marxist social theory, but rather to take certain principles as a given and situate them as the mechanisms of social dynamics in a broader materialist framework. I identify the pitfalls of previous approaches, and take the two most astute constructivist theorists...