Nyorai kuenderera mberi kweiyi ndima - Mukushaikwa kweuto guru reByzantine, vaBulgaria vakapandukirawo pasi paPeter IV weBulgaria
. Nguva yavo yakanga isingagoni kuva iri nani, sezvo Byzantium yakanga ichiri kutambudzwa nokuchinja kwehurumende uye kupamba kunoparadza. Isaac akasarudza kudzikamisa kupandukira kweBulgaria nesimba ndokutungamirira nhimbe yechiuto kuchamhembe. Uto reByzantium rakarwiswa nenzira inoyeuchidza nezveHondo yeManzikert uye kukundikana kwakaitika kare paPliska. Kuedza kwekupedzisira kumanikidza simba reByzantium pamusoro peBulgaria kwakabvumirana nekuedza kwekupedzisira kwaIsaac kwekutonga Humambo; maererano nenyanzvi, kubva ipapo zvichienda mberi, mitemo yaIsaac yaive isingawanzo kupfuura yekudzokorora.