Sarkin Byzantine Michael VIII Palaiologos ya yanke shawarar yin amfani da rashin zaman lafiya a Bulgaria .Ya aika da sojoji don dora abokinsa Ivan Asen III a kan karaga.Ivan Asen III ya sami iko da yankin tsakanin Vidin da Cherven.Mongols sun kewaye Ivailo a Drastar (Silistra) kuma masu girma a babban birnin Tarnovo sun yarda da Ivan Asen III ga Sarkin sarakuna.A cikin wannan shekarar, duk da haka, Ivailo ya sami nasarar yin nasara a Drastar kuma ya nufi babban birnin kasar.Domin ya taimaka wa abokin nasa, Michael na VIII ya aika da sojoji 10,000 zuwa Bulgaria karkashin Murin.Lokacin da Ivailo ya sami labarin wannan kamfen, ya yi watsi da tafiyarsa zuwa Tarnovo.Duk da cewa sojojinsa sun fi yawa, shugaban Bulgaria ya kai hari a Murin a cikin Kotel Pass a ranar 17 ga Yuli 1279 kuma an fatattaki Rumawa gaba daya.Yawancinsu sun mutu a yaƙin, sauran kuma aka kama su kuma aka kashe su da umarnin Ivailo.Bayan shan kaye Michael na VIII ya aika da wani dakaru 5,000 karkashin Aprin amma kuma Ivailo ya ci su kafin ya isa tsaunin Balkan.Ba tare da tallafi ba, Ivan Asen III ya gudu zuwa Constantinople.