The paper deals with the characteristics, modalities and conceptual ground of Foucualt’s understanding of historical analysis. In the first part it focuses on the results yielded by the archeological study of discursive practices. The analysis of its problematic points is followed by the explanation of Foucault’s method called genealogy. Among the results this method has brought the concepts of biopolitics and biopower are underlined. The last part of the study is devoted to Foucault’s reception of the famous Clausewitz’s aphorism concerning the relationship between war and policy.