The Avars (567-822) had advanced from Central Asia to the Caucasus in 558 under the pressure of the Gokturks. The Avars, who lived scattered for a while, settled between the Aral Lake and the Itil River and established sovereignty in these lands. When their territories became small, they met with Emperor Justinian I (527-565) through the Alan Prince Sarosius and formed an alliance with Byzantium. During the reign of Emperor Justinus II (565-578), the relations between the two sides were negatively affected by the territorial demands of the Avars and the intransigent attitude of Bayan Kagan. During the reign of Emperor Mavrikius (582-586), the Avars captured Sirmium (Sremska Mitrovica/Serbia), Singidunum (Belgrade) and Thessalonike (Thessaloniki) and invaded large parts of the Balkans and Greece. The ongoing wars weakened the authority of Mavrikius and discontent grew among the people and the army. As a result of a revolt in the Balkan army, Emperor Mavrikius was deposed from the Byzantine throne in 602 by Phokas, who had a low military rank. This study analyses the effects of the expansion of the Avars in the Balkans on the Byzantine Empire's military strategies, territorial control and internal political balances. The Avar-Byzantine relations that began during the reign of Emperor Justinian I and the subsequent conflicts led to a weakening of the empire's authority, especially during the reign of Mavrikius, when the Avars captured important cities. The study analyses the consequences of these developments on both the external security and internal political stability of Byzantium.

Byzantine Empire, Avars, Emperor Mavrikius, Bayan Khan