Avar Khaganate
The province was located between the Danube river in the north-east and Sava river in the south. The western border of Byzantine Pannonia stretched approximately to the estuary or river Drina into Sava. Important cities in the area were Sirmium and Bassianae. Byzantine Pannonia bordered Byzantine province of Moesia Prima in the south and Avar Khaganate in the west, north and east.