On the Sava: Sirmium becomes Sremska Mitrovica

Sremska Mitrovica is a Serbian city in the Vojvodina on the north bank of the Sava River, which lies on the settlement of the ancient Byzantine city of Sirmium. The former Sirmium during the Middle Ages in Hungarian was "city of Saint Demetrius on the Sava".

The ancient period ends with the conquest of Sirmium by the Avars in 582 and is also an important turning point in the history of southeastern Europe, as the Slavic conquest of land took place with the Avars.

In the Middle Ages, the city was fought over between Byzantium and Hungary for a long time. Methodius of Salonika had his seat as Archbishop of Pannonia and Great Moravia in Sirmium/Sremska Mitrovica in the 9th century. Around 1180 Sremska Mitrovica finally came under Hungarian rule. The city's common medieval name was Civitas Sancti Demetrii, the City of St. Demetrius, which still exists today in the Hungarian Szávaszentdemeter.