This publication recollects four essays presenting a significant change of his interest in research towards a new geographic and cultural region (from the Amazon to the Andean mountains), referring to political and social processes taking place during centuries of a remote past. He extends his objectives of work and investigation thoroughly with a perspective of “Historical Anthropology” and “Ethnohistory”. He is not a historian, and asks the historians for comprehension of his potential errors committed in his “incursion” into their fieldworks; he used some theoretical methods and options having nothing to do with anthropology, in which he had been active for many decades and which has been the subject of his daily academic activity.