Kammala jumla mai zuwa: A farkon karni na 11, yankin da daga baya ya zama Theme na Sirmium ya kasance a cikin iyakokin Daular Bulgaria ta Farko, a ƙarƙashin Tsar Samuil da Duke na gida (voivode) da aka sani da Sermon ya mallaki Sirmium da kewaye. A cikin dogon yaƙi, sarkin Byzantine Basil II
ya ci Bulgaria, kuma ya kafa sabbin jigogi na Byzantine da sauran gwamnonin gida a ƙarƙashin janar ("strategoi") a kan yankunanta. Tsakiyar yankin Samuil ya zama Theme na Bulgaria, yankin arewa maso gabas ya zama Theme na Paristrion, kuma yankin arewa maso yamma ya zama Theme na Sirmium.