Pedzisa mutsara unotevera: Pakutanga kwezana ramakore rechi11, nzvimbo iyo yakazova Theme yeSirmium yaive mukati memiganhu yeFirst Bulgarian Empire, pasi paTsar Samuil uye mutongi wemunharaunda (voivode) anozivikanwa seSermoni akatonga pamusoro peSirmium nenzvimbo dzakapoteredza. Muhondo refu, mambo weByzantium Basil II
Bulgaria, uye yakatanga misoro mitsva yeByzantine nedzimwe hurumende dzemunharaunda 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.