The task of the study presented in the book is to determine the forms and composition of the elite of Old Russian society in the X-XI centuries, especially that part of it that participated in making the most important military and political decisions. The data of the ancient annals, treaties of Russia and Byzantium of the 10th century, "Russian Truth" and other sources in a wide comparative historical perspective are analyzed. The groups that in the XI century. made up the most important elements of the elite of Russia - nobility (boyars) and military servants of princes (youths or grids).