This paper relates diachronic change in discourse strategies of the Viking-age historical writing to political changes of the period and to communities of practice that produce these histories and chronicles. It examines the labels and stereotypes applied to the Vikings and establishes their sources and evolution by applying a fourfold chronological division of historical sources from around 800 to 1200 (based on the political developments within Anglo-Saxon history and on the manuscript history of the Anglo-Saxon Chronicle). The data for the study come from both Old English and Anglo-Latin chronicles. The results are interpreted in terms of critical discourse analysis. It is demonstrated that the chroniclers employ strategies of dissimilation exploiting the notion of illegitimacy and criminality of the Viking outgroup. These strategies change over time, depending on the political situation (raiding vs. settlement vs. reconquest period) and communities of practice involved in the maintenance and dissemination of a particular political discourse.