A cikin 998, Samuel ya kaddamar da wani babban kamfen a kan Duklja don hana kawance tsakanin Yarima Jovan Vladimir da Rumawa.Lokacin da sojojin Bulgaria suka isa Duklja, yarima na Serbia da mutanensa suka janye zuwa tsaunuka.Sama'ila ya bar wani ɓangare na sojojin a gindin duwatsu kuma ya jagoranci sauran sojojin suka kewaye katangar bakin teku na Ulcinj.A ƙoƙarin hana zubar da jini, ya nemi Jovan Vladimir ya mika wuya.Bayan da yariman ya ƙi, wasu sarakunan Sabiyawan sun ba da hidima ga Bulgarian kuma, lokacin da ya bayyana cewa ƙarin juriya ba ta da amfani, Sabiyawan sun mika wuya.An kai Jovan Vladimir zaman gudun hijira zuwa fadar Samuel a Prespa.Sojojin Bulgaria sun ci gaba da wucewa ta Dalmatiya, suna iko da Kotor kuma suna tafiya zuwa Dubrovnik.Ko da yake sun kasa ɗaukar Dubrovnik, sun lalata ƙauyukan da ke kewaye.Daga nan ne sojojin Bulgaria suka kai wa Croatia hari domin nuna goyon bayansu ga yarima Krešimir na III da Gojslav na 'yan tawaye kuma suka ci gaba da zuwa arewa maso yamma har zuwa Split, Trogir da Zadar, sannan arewa maso gabas ta Bosnia da Rashka suka koma Bulgaria .Wannan Yaƙin Croato-Bulgaria ya ƙyale Sama’ila ya kafa sarakunan vassal a Croatia.Dan uwan ​​Samuel Kosara ya yi soyayya da Jovan Vladimir da aka kama.Ma’auratan sun yi aure bayan sun sami amincewar Samuel, kuma Jovan ya koma ƙasarsa a matsayin jami’in Bulgaria tare da kawunsa Dragomir, wanda Samuel ya amince da shi.A halin yanzu, Gimbiya Miroslava ta ƙaunaci Bazantin mai martaba ɗan fursuna Ashhot, ɗan Gregorios Taronites, mataccen gwamnan Tasalonika, kuma ya yi barazanar kashe kansa idan ba a bar ta ta aure shi ba.Sama'ila kuwa ya yarda, ya naɗa Ashot hakimin Dirakiya.Sama'ila ya kuma kulla yarjejeniya da Magyars lokacin da babban dansa kuma magaji, Gavril Radomir, ya auri 'yar Babban Yariman Hungarian Géza.