The subject of legitimacy is well-trodden ground for political scientists, philosophers and sociologists, as the functions of myth are for anthropologists. Historians have also considered these subjects, not least in respect of Eastern Europe, though their contributions are scattered. But little attention has been paid to the broad issues of long-term changes and continuities in the methods of political legitimisation, and of the use of myths for legitimating purposes in eastern Europe. This chapter addresses the gap in the literature, offering a preliminary sketch of the major trends and tendencies since the Byzantine period.