This thesis is the result of a research project supported by Sida-SAREC, the Swedish Agency for Research Co-operation with Developing Countries. The region of the Lake Poopó in the Bolivian plateau (Altiplano) was selected as the research area. The thesis focuses on the topic of Bolivian Indians, such as the ones called Urus, who are assimilated to ethnic groups as a consequence of the colonial past, among others. An understanding of the complexity of this construction draws from disciplines such as Anthropology, Archaeology, History, and Sociology inter alia, in an effort to expose the power relations behind the construction and to contribute with a perspective to an understanding of multi-cause phenomena.