. . Remains of Sirmium stand on the site of the modern-day
Sremska Mitrovica, west of
Belgrade (Roman
Singidunum). It was located west of
Bassianae and of
Viminacium, southwest of
Cusum, southeast of
Cuccium and southwest of
Cibalae. Archaeologists have found traces of organized human life on the site of Sirmium dating from 5,000 BCE. The city was first mentioned in the 4th century BC and was originally inhabited by the
Illyrians and
Celts (by the Pannonian-Illyrian Amantini and the Celtic
Scordisci). The
Triballi king
Syrmus was later considered the
eponymous founder of Sirmium, but the roots are different, and the two words only became conflated later. The name Sirmium by itself means "flow, flowing water, wetland", referring to its close river position on the nearby
Sava. With the Celtic tribe of
Scordisci as allies, the Roman
proconsul Marcus Vinicius took Sirmium in around 14 BC. In the 1st century AD, Sirmium gained the status of a Roman colony, and became an important military and strategic center of the
Pannonia province. The Roman emperors
Trajan,
Marcus Aurelius, and
Claudius II prepared war expeditions in Sirmium. In 103, Pannonia was split into two provinces:
Pannonia Superior and
Pannonia Inferior; Sirmium became the capital city of the latter. In 296,
Diocletian reorganized Pannonia into four provinces:
Pannonia Prima,
Pannonia Valeria,
Pannonia Savia and
Pannonia Secunda, with Sirmium becoming the capital of Pannonia Secunda. He joined them with
Noricum and
Dalmatia to establish the
Diocese of Pannonia, with Sirmium as its capital also. In 293, with the establishment of the
Tetrarchy, the Roman Empire was split into four parts; Sirmium emerged as one of the four capital cities (along with
Trier,
Mediolanum, and
Nicomedia), and was the capital of emperor
Galerius. With the establishment of
Praetorian prefectures in 318, the capital of the prefecture of
Illyricum was Sirmium, remaining so until 379, when the westernmost Diocese of Illyricum, Pannonia (including Sirmium), was detached and joined to the prefecture of
Italia assuming the name of
Diocese of Illyricum. The eastern part of Illyricum remained a separate prefecture under the East Roman (Byzantine) Empire with its new capital in
Thessalonica. The city also had an imperial palace, a horse-racing arena, a
mint, an arena theatre, and a theatre, as well as many workshops, public baths, temples, public palaces, and luxury villas. Ancient historian
Ammianus Marcellinus called it "the glorious mother of cities". The mint in Sirmium was connected with the mint in
Salona and silver mines in the
Dinaric Alps through the
Via Argentaria. At the end of the 4th century, Sirmium came under the sway of the
Goths, and later, was again annexed to the East Roman Empire. In 441 the
Huns conquered Sirmium; for more than a century it was held by various other tribes, such as the
Ostrogoths and
Gepids. In 504, Ostrogothic Count Pitzas under
Theoderic the Great took Sirmium. For a short time, Sirmium was the center of the
Kingdom of the Gepids, and king
Cunimund () minted gold coins there. After 567, Sirmium was returned to the East Roman Empire. The
Pannonian Avars conquered and destroyed the city in 582. The city was also the location of the
Battle of Sirmium that took place in 1167, where a Roman army dispatched by
Manuel I Komnenos decisively defeated the forces of Hungary, turning the latter into a satellite state. ==Roman emperors==