Bulgeriya ta zama babbar ikon kudu maso gabashin Turai bayan yakin Klokotnitsa.Sojojin Ivan sun shiga cikin ƙasashen Theodore kuma sun mamaye garuruwan Epirote da dama.Sun kama Ohrid, Prilep da Serres a Makidoniya, Adrianople, Demotika da Plovdiv a Thrace kuma sun mamaye Great Vlachia a Thessaly.An kuma hade daular Alexius Slav a cikin tsaunin Rhodope.Ivan Asen ya sanya rundunonin sojan Bulgeriya a cikin muhimman kagara kuma ya naɗa mutanensa don su ba su umarni da karɓar haraji, amma jami’an yankin sun ci gaba da gudanar da wasu wurare a yankunan da aka ci nasara.Ya maye gurbin bishop na Girka da limaman Bulgaria a Makidoniya.Ya ba da kyauta mai karimci ga gidajen ibadar da ke Dutsen Athos a lokacin ziyararsa a shekara ta 1230, amma bai iya rinjayar sufaye su amince da ikon babban cocin Bulgarian ba.Surukinsa, Manuel Doukas, ya mallaki Daular Tasalonika.Sojojin Bulgaria kuma sun kai farmaki kan Serbia, saboda Stefan Radoslav, Sarkin Sabiya, ya goyi bayan surukinsa, Theodore, a kan Bulgaria.Yunkurin Ivan Asen ya tabbatar da ikon Bulgarian ta hanyar Via Egnatia (muhimmin hanyar kasuwanci tsakanin Tasalonika da Durazzo).Ya kafa mint a Ohrid wanda ya fara buga tsabar zinare.Yawan kudaden shiga da ya samu ya ba shi damar cim ma wani babban shiri na gini a Tarnovo.Cocin Mai Tsarki Arba'in Shahidai, wanda aka yi masa ado da fale-falen fale-falen fale-falen fale-falen buraka da zane-zane, sun yi bikin tunawa da nasarar da ya samu a Klokotnitsa.An faɗaɗa fadar sarki da ke Dutsen Tsaravets.Rubutun tunawa a ɗaya daga cikin ginshiƙan Cocin na Shahidai Arba'in Mai Tsarki ya rubuta nasarar da Ivan Asen ya yi.Ana kiransa da "tsarki na Bulgaria, Girkawa da sauran kasashe", yana nuna cewa yana shirin farfado da daular Rumawa a karkashin mulkinsa.Ya kuma naɗa kansa sarki a cikin wasiƙarsa na ba da kyauta ga gidan ibada na Vatopedi da ke Dutsen Athos da kuma takardar shaidarsa game da gata na ƴan kasuwan Ragusan.Ya yi koyi da sarakunan Rumawa, ya rufe hayarsa da bijimai na zinariya.Ɗaya daga cikin hatiminsa ya nuna shi sanye da alamar sarauta, kuma yana bayyana burinsa na sarauta.