The aim of the paper is twofold. On the one hand, it examines the epistemological reasons behind the shifting beginnings of Byzantine literature, a shift that covers a period of four centuries (AD 300-700), as well as the methodological problems for the study of Byzantine literature resulting from the rise of Late Antiquity as a new historical period and a new field of studies. On the other hand, the paper proposes a series of four textually immanent criteria and seven internal operative principles by means of which a different methodological approach to the «beginning» of Byzantine literature can be reached. For this purpose Eusebios of Caesarea and Lactantius will be used as the textual basis for establishing a structural break in literary production in the first two decades of the fourth century. For the purpose of controlling this proposal a comparison with an important but highly debated monument (the Arch of Constantine in Rome) will be made and some final conclusions as to the course of Greek literature in early Byzantine times will be made.