A cikin shekaru bayan samun 'yancin kai, Bulgeriya ta ƙara zama soja kuma ana kiranta da "Balkan Prussia", dangane da sha'awarta na sake fasalin yarjejeniyar Berlin ta hanyar yaki.^[40] Rarraba yankuna a cikin Balkan da Manyan Mahukunta suka yi ba tare da la'akari da tsarin kabilanci ba ya haifar da rashin jin daɗi ba kawai a Bulgaria ba, har ma a cikin ƙasashe makwabta.A shekara ta 1911, firaministan kasar Ivan Geshov ya kulla kawance da kasashen Girka da Sabiya domin hada kai da Ottoman tare da sake duba yarjejeniyoyin da ake da su dangane da kabilanci.^[41]A watan Fabrairun 1912 an sanya hannu kan wata yarjejeniya ta sirri tsakanin Bulgaria da Serbia kuma a watan Mayu 1912 aka kulla irin wannan yarjejeniya da Girka.An kuma kawo Montenegro cikin yarjejeniyar.Yarjejeniyar ta tanadi raba yankunan Makidoniya da Thrace tsakanin abokan kawance, duk da cewa an bar layukan rarrabuwar kawuna cikin hadari.Bayan da Daular Usmaniyya ta ki aiwatar da sauye-sauye a yankunan da ake takaddama a kai, yakin Balkan na farko ya barke a watan Oktoban shekarar 1912 a daidai lokacin da Daular Usmaniyya ta daure a wani gagarumin yaki da Italiya a kasar Libiya.Kawayen sun yi nasarar fatattakar Daular Usmaniyya cikin sauki tare da kwace mafi yawan yankunansu na Turai.^[41]Bulgeriya ta sami asarar mafi muni na kowane ɗaya daga cikin ƙawayen yayin da kuma suka yi iƙirarin yanki mafi girma.Sabis ɗin musamman ba su yarda ba kuma sun ƙi barin kowane yanki da suka ƙwace a arewacin Makidoniya (wato yankin da ya yi daidai da Jumhuriyar Arewacin Macedonia ta zamani), suna cewa sojojin Bulgeriya sun kasa cim ma burinsu. burin yaki a Adrianople (don kama shi ba tare da taimakon Serbia ba) da kuma cewa yarjejeniyar kafin yakin a kan rabon Macedonia dole ne a sake bitar.Wasu da'irar a Bulgaria sun karkata zuwa yaƙi da Sabiya da Girka a kan wannan batu.A cikin watan Yunin 1913, Serbia da Girka suka kulla sabuwar kawance da Bulgaria.Firayim Ministan Serbia Nikola Pasic ya yi wa Girka Thrace alkawari ga Girka idan ta taimaka wa Serbia ta kare yankin da ta kama a Macedonia;Firayim Ministan Girka Eleftheros Venizelos ya amince.Ganin hakan a matsayin cin zarafin yarjejeniyoyin da aka cimma kafin yakin, kuma Jamus da Ostiriya-Hungary suka karfafa shi a asirce, Tsar Ferdinand ya shelanta yaki akan Serbia da Girka a ranar 29 ga watan Yuni.Da farko an buge sojojin Serbia da na Girka daga kan iyakar Bulgaria da ke yammacin kasar, amma cikin sauri suka samu nasara tare da tilastawa Bulgaria ja da baya.Fadan ya yi muni matuka, inda aka samu hasarar rayuka da dama, musamman a lokacin da aka yi yakin Bregalnitsa mai muhimmanci.Ba da daɗewa ba, Romania ta shiga yaƙin da ke gefen Girka da Sabiya, suka kai wa Bulgaria hari daga arewa.Daular Usmaniyya ta dauki wannan a matsayin wata dama ta sake dawo da yankunanta da suka bata sannan kuma ta kai hari daga kudu maso gabas.Yayin da take fuskantar yaki a bangarori uku daban-daban, Bulgaria ta kai karar neman zaman lafiya.An tilastawa barin yawancin yankunan da ta mallaka a Macedonia zuwa Serbia da Girka, Adrianpole zuwa Daular Ottoman, da yankin Kudancin Dobruja zuwa Romania.Yaƙe-yaƙe guda biyu na Balkan sun lalata Bulgaria sosai, sun dakatar da ci gaban tattalin arziƙinta har ya zuwa yanzu, kuma sun bar mutane 58,000 suka mutu, sama da 100,000 suka jikkata.Haushin da aka yi na cin amanar tsoffin abokansa ya ba da damar ƙungiyoyin siyasa waɗanda suka nemi maido da Macedonia zuwa Bulgaria.^[42]