Nyorera kuenderera kweiyi ndima - Pakutanga kwezana ramakore rechi11, nzvimbo iyo yakazove iyo Sirmium Theme yaive mukati memiganhu yeFirst Bulgarian Empire, pasi paCzar Samuil uye mutongi wemuno (voivode) anozivikanwa saSermon akatonga Sirmium nenzvimbo dzakatenderedza. Muhondo yakareba, mambo weByzantium Basil II akakunda Bulgaria
, uye vakagadzira misoro mitsva yeByzantine nedzimwe hurumende dzemuno pasi pevakuru vakuru ("strategoi") munharaunda yayo. Chikamu chepakati cheumambo hwaSamueri chakava Theme yeBulgaria, chikamu chokuchamhembe kwakadziva kumabvazuva Theme yeParistrion, uye chikamu chokuchamhembe kwakadziva kumadokero chakava Theme yeSirmium.