Sirmium
Sirmium was a city in the Roman province of Pannonia , located on the Sava river , on the site of modern Sremska Mitrovica in northern Serbia . 
<triplet> Sirmium <subj> Pannonia <obj> located in the administrative territorial entity <triplet> Pannonia <subj> Roman <obj> time period <triplet> Sremska Mitrovica <subj> Serbia <obj> country