Battles of Viminacium
599 CE.
Shown on the map at 44.712°, 21.169°.
The Battles of Viminacium were a series of three battles fought against the Avars by the Eastern Roman Empire. They were decisive Roman successes, which were followed by an invasion of Pannonia. In summer 599, the East Roman Emperor Maurice sent his generals Priscus and Comentiolus to the Danube front against the Avars. The generals joined their forces at Singidunum and advanced together down the river to Viminacium. The Avar khagan Bayan I meanwhile - learning that the Romans had determined to violate the peace - crossed the Danube at Viminacium and invaded Moesia Prima, while he entrusted a large force to four of his sons, who were directed to guard the river and prevent the Romans from crossing over to the left bank. In spite of the presence of the Avar army, however, the Byzantine army crossed on rafts and pitched a camp on the left side, while the two commanders sojourned in the town of Viminacium, which stood on an island in the river.
Text from the Wikipedia article Battles of Viminacium, licensed CC BY-SA 4.0.