 When the Byzantine Empire was unable to pay subsidies or hire Avar mercenaries, the Avars raided their Balkan territories.According to Menander, Bayan commanded an army of 10,000 Kutrigur Bulgars and sacked Dalmatia in 568, effectively cutting the Byzantine terrestrial link with North Italy and Western Europe.By 582, the Avars had captured Sirmium, an important fort in Pannonia.