The article is devoted to the study of medieval Scandinavian and domestic narrative sources for information about the peculiarities of the military confrontation and interaction between the Varangians and Ancient Rus. On the basis of the analyzed materials conclusions have been made about the necessity of applying the method of comparative analysis when considering medieval Nordic narrative sources, and also about the peculiarities and substantive changes of Russian-Scandinavian relations during the period VI–XIV centuries: the battles between the Varangians and Rus were fought both on land and at sea, across a vast geographical area; the analyzed sources show evidence of military interaction between the Varangians and Ancient Rus through the recruitment of individual detachments, military aid and dynastic alliances; the character of the military confrontation between the Varangians and Rus is traced as the principles of warfare change by the XIV century.