 When the Byzantines refused to increase the stipend amount as requested by Bayan's son and successor Bayan II (from 584), the Avars proceeded to capture Singidunum and Viminacium.They suffered setbacks, however, during Maurice's Balkan campaigns in the 590s.By 600 the Avars had established a nomadic empire ruling over a multitude of peoples and stretching from modern Austria in the west to the Pontic–Caspian steppe in the east.