This paper is a scholarly review of the study of the contemporary famous Russian Byzantine scholar Аndrey Yurʹevich Mitrofanov Emperor Аlexios I Komnenos and His Strategy, published in June 2020. This monograph is extremely important for the Russian humanities scholarship: it is the first generalizing and comprehensive study in Russian devoted to the military policy of the Byzantine Emperor Alexios I Komnenos. The reign of this emperor (1081-1118) coincided in time with the first Crusades of Western European knights against the Seljuq Turks, therefore A. Yu. Mitrofanov considers the military reforms and campaigns of Alexios I in a broad geopolitical context. He examined the hostilities, campaigns and expeditions of the Byzantine troops, as well as their tactics and strategy, inextricably linked with the international position of Byzantium, the church policy of Alexios I and his diplomatic activities, and also, which is especially important, with the level of development of military science at that time. It is important to emphasize that the author of the monograph successfully and organically combines the analysis of event history, the history of structures and source analysis in the text, focusing on the genre features of the Alexiad, a historical chronicle about the reign of Alexios I and his deeds. Of course, the researcher also examines in detail the worldview of the author of the Alexiad - the Byzantine princess Anna Komnene, daughter of Alexios I, and convincingly proves that she has deep and systematic knowledge in the field of military theory.