 Nyora kupfuurira kweiyi ndima - Sviatoslav akadzokera kuDorostolon, iyo mauto eByzantine akakomba kwemazuva makumi matanhatu nemashanu. Akaparadzaniswa uye akakomberedzwa, Sviatoslav akaita chibvumirano naJohn ndokubvuma kusiya Balkan, kurega zvaaiti ndezvokumaodzanyemba kweCrimea, uye kudzokera kumadokero kwerwizi rwaDnieper. Mukutsinhana, mambo weByzantium akapa Rus zvokudya uye nzira yakachengeteka yokudzokera kumusha. Sviatoslav nevarume vake vakafamba nechikepe ndokusvika paBerezan Island pamuromo weDnieper, kwavakavaka musasa munguva yechando. Mwedzi inoverengeka gare gare, maererano nePrimary Chronicle, musasa wavo wakaparadzwa nenzara, zvokuti kunyange musoro webhiza waisagona kutengwa nemari isingasviki hafu yegrivna. Nepo hondo yaSviatoslav isina kuunza zvibereko zvinooneka kuRus, yakaderedza hurumende yeBulgaria uye yakaisiya ichinetseka nekurwiswa kwaBasil muBulgar-Mhondi makumi mana emakore gare gare. 