A karkashin mulkin Asparuh, Bulgaria ta fadada kudu maso yamma bayan yakin Ongal da Danubian Bulgaria da aka kirkiro.Dan kuma magajin Asparuh Tervel ya zama mai mulki a farkon karni na 8 lokacin da Sarkin Rumawa Justinian II ya nemi Tervel ya taimaka wajen dawo da karagarsa, wanda Tervel ya karbi yankin Zagore daga Masarautar kuma aka biya shi zinare masu yawa.Ya kuma sami lakabin Byzantine "Kaisar".Bayan mulkin Tervel, ana yawan samun sauye-sauye a majalissu masu mulki, wadanda ke haifar da rashin zaman lafiya da rikicin siyasa.Shekaru da yawa bayan haka, a cikin 768, Telerig na gidan Dulo, ya mallaki Bulgaria.Yaƙin sojan da ya yi a kan Constantine V a shekara ta 774, bai yi nasara ba.A karkashin mulkin Krum (802-814) Bulgaria ta faɗaɗa arewa-maso-yamma da kudu, ta mamaye ƙasashen da ke tsakanin kogin Danube na tsakiya da Moldova, duk ƙasar Romania ta yau, Sofia a 809 da Adrianople a 813, tare da yin barazana ga Constantinople kanta.Krum ya aiwatar da garambawul na doka da nufin rage talauci da karfafa alakar zamantakewa a cikin jiharsa mai girman gaske.A lokacin mulkin Khan Omurtag (814-831), iyakokin arewa maso yamma tare da daular Frankish an daidaita su tare da tsakiyar Danube.An gina wani katafaren fada, gidajen ibada na arna, wurin zama na masu mulki, kagara, kagara, gidajen ruwa da wuraren wanka a Pliska babban birnin Bulgeriya, akasari na dutse da bulo.A ƙarshen karni na 9 da farkon 10th, Bulgaria ta ƙara zuwa Epirus da Thessaly a kudu, Bosnia a yamma kuma ta mallaki dukkanin Romania na yau da gabashin Hungary zuwa arewa suna haɗuwa da tsofaffin tushen.Ƙasar Serbia ta samo asali ne a matsayin abin dogaro ga daular Bulgaria.A karkashin Tsar Simeon I na Bulgaria (Simeon the Great), wanda ya yi karatu a Konstantinoful, Bulgaria ta sake zama babbar barazana ga Daular Byzantine.Manufarsa mai tada hankali ita ce ta kawar da Byzantium a matsayin babban abokin tarayya na siyasar makiyaya a yankin.Bayan mutuwar Saminu, Bulgeriya ta sami rauni ta hanyar yaƙe-yaƙe na waje da na ciki da Croatians, Magyars, Pechenegs da Sabiyawa da yaduwar bidi'a ta Bogomil.[ ^{[23] []} Rikicin Rus da Rumawa guda biyu a jere ya haifar da kwace babban birnin kasar Preslav a hannun sojojin Byzantine a shekara ta 971.^[25]A shekara ta 986, Sarkin Byzantine Basil II ya ɗauki yakin neman cin nasara a Bulgaria.Bayan yakin da ya dauki tsawon shekaru da dama ya yi wa Bulgeriya a shekara ta 1014 ya kuma kammala yakin shekaru hudu bayan haka.A cikin 1018, bayan mutuwar Tsar Bulgarian na ƙarshe - Ivan Vladislav, yawancin manyan sarakunan Bulgaria sun zaɓi shiga daular Roman ta Gabas.^[26] Duk da haka, Bulgaria ta rasa 'yancin kanta kuma ta kasance ƙarƙashin mulkin Byzantium fiye da karni daya da rabi.Da rugujewar jihar, cocin Bulgaria ya fada karkashin mamayar limaman Bizantine wadanda suka karbe iko da Archbishop na Ohrid.