This article, focusing on ‘Empire and the unification of social structures’, researched the meaning of the byzantine confrontation on the Bogomils in the politics, military relations and socio-economic problems from the middle of the tenth century to the middle of the twelfth century. So, I analyzed a letter from Patriarch Theophylact of Constantinople to Tsar Peter of Bulgaria, the work of Euthymius Zigabenus, the polemic Discourse against the Heresy of Bogomil written by Cosmas the Priest, a 10th-century Bulgarian official. King Simeon`s death in 927 left Bulgaria exhausted. Bulgaria had to face serious internal problems. One of them was the heretical movement started under Simeon`s son and successor, Peter. Based upon the conception of earlier Eastern sects as to a permanent struggle between the forces of good and evil, Bogomilism was a Gnostic religiopolitical sect founded in the First Bulgarian Empire by the priest Bogomil during the reign of Tsar Petar I in the 10th century. It most probably arose in what is today the region of Macedonia as a response to the social stratification that occurred as a result of the introduction of feudalism and as a form of political movement and opposition to the Bulgarian state and the church. The Bogomils called for a return to early Christianity, rejecting the ecclesiastical hierarchy, and their primary political tendencies were resistance to the state and church authorities. This helped the movement spread quickly in the Balkans, gradually expanding throughout the Byzantine Empire and later reaching Kievan Rus`, Bosnia, Dalmatia, Rascia, Italy, France. Bogomilism was an outcome of many factors that had arisen in the beginning of 10th century, most probably in the region of Macedonia. It was also strongly influenced by the Paulicians who had been driven out of Armenia. The Church in Bulgaria tried to extirpate Bogomilism. Tsar Peter of Bulgaria asked the Byzantine Empire to help to solve problems of Bogomilism. But Patriarch Theophylact of Constantinople gave a several advises to Tsar Peter of Bulgaria. It was not an aggressive attitude, but a passive-negative attitude. Although the heresy was poorly regarded officially, such was the Byzantine Empire`s need for manpower that Alexius I Comnenus raised a unit of Bulgarian dualists from the neighbourhood of Philippopolis(now Plovdiv). Alexius did not proceed further against the dualist heretics until the last two years of his reign. At that time, under pressure from the Church to establish religious conformity, many Bogomils were forcibly converted, and their leaders either imprisoned or executed.