The monograph offers a global view of the Byzantine-Avar relations at political, diplomatic and cultural level. Its main contribution consists in the reconstruction of these relations after 626 -when the written sources are very few- and the definition of the possible channels of communication between the two sides, taking into account the historical data to the northwestern Adriatic Sea, the Balkan Peninsula and the Byzantine Crimea. For the 7th and 8th centuries, focus point are the Byzantine objects in the Avar khaganate as well as those constructed on Byzantine patterns (jewellery, belt fittings, buckles, etc.). Under consideration are also the numismatic finds. Furthermore, other issues are critically approached, such as the view that the Avars had acquired the status of foederati with the treaty of 558, the reasons for the failure of Maurice’s military operations against the Avars from 592 to 602, the conflicts at the periphery of the Avar khaganate (Samo, Croats and Serbs, Kubrat) and the possible involvement of Byzantium, the influences of both sides on the art of war etc.