The article is devoted to the identification and description of the features of the diplomacy of the Early Byzantine government in the least studied period in science in the VI century. For the first time in historiography, a comprehensive analysis of these sources is given, describing not only the activities of emperors, but also the actions of their allies and opponents. The characteristic details of Byzantine-Avar relations in all the main areas of foreign policy of that time are corrected and refined. An original conclusion is made about the expedient and active politics of the late Justinian era and its successors