Bayan I Bayan I was an Avar khagan , between 562 and 602 . As the Göktürk Empire expanded westwards , Bayan Khagan led a group of Avars and Bulgars out of their reach , eventually settling in Pannonia in 568 . Raids against the Franks and Lombards . In 562 , the Avars and Bulgars had reached the Lower Danube : it was most likely in that year that Bayan became their supreme Khagan , as his predecessor , the Kutrigur Khan Zabergan had died . As allies of the Byzantine Empire , then ruled by Justinian I , the Avars had obtained a grant of gold to crush other nomads — the Sabirs , Utigurs , Kutrigurs and Saragurs - in the lands later known as Ukraine , a task they accomplished to the emperor ' s satisfaction . Bayan ' s Avars now exacted the renewal of the alliance , increased pay and a land to live in . Bayan had eyed the plain of Moesia , just south of the Lower Danube , what would become northern Bulgaria , as his promised land , but the Byzantines were adamant the Avars should not in any case cross the river . So Bayan and his horde in 563 rode around the northern Carpathians to Germany , where they were soundly stemmed along the river Elbe by the Frankish king Sigebert I of Austrasia . This defeat induced them to come back on their footsteps to the Lower Danube region . After vainly trying to force the Danubian border when the new Byzantine emperor Justin II denied them both entry and wage , the Avars renewed their ride to Thuringia . This time ( 566 ) they did defeat Sigebert , but had nonetheless to stop ; in the meantime the Göktürks , in pursuit of their former subjects , remained a real danger . The Avars , traditionally a nomadic people , desperately needed both shelter and pasture for their livestock , but the route to Pannonia was blocked by impassable mountains covered with thick forests : the Carpathian range . It was in the critical winter of 566 - 567 that the Avars , stuck in what is now eastern Germany , were sent feelers by Alboin , the strong ruler of the Lombards and brother - in - law of Sigebert , who sought an alliance to crush his old enemies the Gepids . These last ones , by chance , controlled the only practical way from the Lower Danube to the craved Pannonian pastures . So in 567 king Cunimund ' s Gepid kingdom was attacked by two directions : from the west came the Lombards , from the north , through Moravia and the Danube , the Avars . Bayan crushed Cunimond ' s forces and made a cup from his defeated enemy ' s skull as a present ( and warning ) for his ally Alboin ( who is famously quoted as having forced Cunimond ' s daughter Rosamund , whom he had taken as war bride , to drink from it , sealing his own fate ) . Then the Avar horde marched against Sirmium , by now firmly held by Gepid remnants and a Byzantine garrison led by general Bonosus . In the meantime large numbers of Slavs settled in Pannonia in the wake of the Avars ; and in 568 Alboin and his Lombards deemed it wise to move for the half - ruined but promising lands of Italy where they would establish a long - lasting kingdom . They concluded however a treaty with the Avar Khagan so as they could reenter parts of Pannonia and Noricum ( Austria ) if they chose so in the future , then departed with large numbers of the vanquished Gepids and a host of other Germanic tribes . Wars with Byzantium . After ten years of uneasy , undocumented peace , Bayan again marched against Sirmium , wresting it from Byzantine hands after a two - year siege , then took also Singidunum , evicting the Byzantines from the inner Balkans and opening the area to an unstoppable influx of Slavs , that in five years at most flooded all the semi - abandoned region down to the Peloponnesus . It was the year 582 : Bayan was now able to attack the Byzantines in Thrace , and when Tiberius II Constantine , who had failed in stopping him , was succeeded in Constantinople by his son - in - law Maurice , he managed to extract a huge tribute in gold : 100 , 000 gold coins , or some 1 , 000 lbs , per year . In later times Avars and Slavs still raided the remaining Byzantine lands as Maurice was hard pressed to defend his native Cappadocia and Armenia from the mighty Sassanians of Persia . By 592 the Byzantine ruler , once he defeated the Persian menace , was bent on revenge and counterattacked in full force , soon reverting the roles ( see Maurice ' s Balkan campaigns ) . Repeated , massive defeats shook the Avaro - Slavic hordes as strong organized Byzantine armies penetrated north of the Danube into Wallachia , and eventually , under general Priscus , crushed the enemy along the river Tisza in the very heart of Pannonia . It was Phocas ' rebellion against Mauricein 602 what ultimately saved the Avars and almost terminated , on the other hand , the Byzantine empire . In the same year Khagan Bayan died , his empire now safe and firmly established . Notes . References .