Sremska Mitrovica is a city and the administrative center of the Srem District in the autonomous province of Vojvodina, Serbia. It is situated on the left bank of the Sava river. As of 2022, the city has a total population of 40,144 inhabitants, while its administrative area has a population of 72,580 inhabitants.
As Sirmium, it was a capital of the Roman Empire during the Tetrarchy of 4th century CE. Ten Roman emperors were born in or near this city, Emperors Herennius Etruscus, Hostilian, Decius Traian, Claudius Gothicus, Quintillus, Aurelian, Probus, Maximian, Constantius II and Gratian.
Wikipedia https://en.wikipedia.org/wiki/Sremska_Mitrovica
Coordinates 44°58'12.595" N 19°36'44.688" E