A cikin karni na 4, ƙungiyar Goths ta isa arewacin Bulgaria kuma suka zauna a ciki da kewayen Nicopolis ad Istrum.A wurin, bishop na Gothic Ulfilas ya fassara Littafi Mai Tsarki daga Hellenanci zuwa Gothic, yana ƙirƙirar haruffan Gothic a cikin aikin.Wannan shi ne littafi na farko da aka rubuta a cikin harshen Jamusanci , don haka aƙalla wani masanin tarihi ya kira Ulfilas a matsayin "uban adabin Jamus".^[17] An kafa gidan sufi na Kirista na farko a Turai a cikin 344 ta Saint Athanasius kusa da Chirpan na zamani bayan Majalisar Serdica.^[18]Saboda yanayin karkara na mutanen yankin, ikon da Romawa ke da shi a yankin ya kasance mai rauni.A cikin karni na 5, Attila's Huns sun kai hari a yankunan Bulgeriya a yau kuma sun washe matsugunan Romawa da yawa.A ƙarshen karni na 6, Avars ya shirya kai hare-hare na yau da kullun zuwa arewacin Bulgaria, wanda ya kasance farkon isowar Slavs.A cikin karni na 6, al'adun gargajiya na Greco-Roman har yanzu suna da tasiri, amma falsafar Kiristanci da al'adun Kirista sun mamaye kuma suka fara maye gurbinsa.^[19] Daga karni na 7, Girkanci ya zama babban yare a cikin mulkin daular Roman ta Gabas, Coci da jama'a, ya maye gurbin Latin.^[20]