ɐ kˈɑːntɹækt fɹʌm fˈaɪvhˈʌndɹɪd tˈɛn ɐsˈaɪnd mˈoʊst əv ðə tˈɛɹɪtˌoːɹi ʌv fˈɔːɹmɚ ɹˈoʊmən pænˈoʊniə ɪŋklˈuːdɪŋ sˈɜːmiəm tə ðɪ ˈɑːstɹəɡˌɑːθs, wˌaɪl ðɪ ˈiːstɚn pˈɑːɹt ʌv pɹˈɛzəntdˈeɪ sˈɪəmˌiə wˌɪtʃ ɪŋklˈuːdᵻd ðə sˈɪɾi ʌv bˈæsiənˌiː wʌz ɐsˈaɪnd tə ðə bˈɪzɐntˌiːn ˈɛmpaɪɚ.
A contract from 510 assigned most of the territory of former Roman Pannonia (including Sirmium) to the Ostrogoths, while the eastern part of present-day Syrmia (which included the city of Bassianae) was assigned to the Byzantine Empire.