The numerous wars waged by Simeon, however, and his ambitious building programme had drained the resources of the country and proved a burden which the people were unable to support. At the same time, the development of feudal relations had turned the majority of the Bulgarian peasants from independent landowners into was seething among them. At the time when the Bulgarians were converted to Christianity, the Christian Church already had a biography which was five centuries old, which had led it away from the humane and democratic principles of Early Christianity and had turned it lastingly into a powerful ideological and political institution whose entire activity was aimed at preserving and consolidating the existing feudal social order. What is more, the Church itself was a big feudal landowner with definite administrative and juridical functions, and the supreme clergy was a component of the ruling feudal class. In such conditions and in view of the predominant religious world outlook among the people, the popular discontent inevitably acquired a religious form.
Thanks to the epoch-making work of Cyril and Methodius, there was a popular rural intelligentsia in Bulgaria of a scope inconceivable for the ‘new’ west- European states, where literary language and vernacular were divorced. The literate people, who had read religious books, were not slow in perceiving the gap separating the social order sanctioned by the church and the principles embodied in the Bible, so that many of them became ideologists of the people’s discontent. Thus, in the 920s the Bogomil movement came into being, which was also known as ‘the Bulgarian heresy’ – one of the most powerful heretic movements of the early Middle Ages. It was religious in form and profoundly social in content: it was the movement of the dependent peasantry and urban poor against the feudal social system.
The Bogomil movement got its name from its initiator- Priest Bogomil. Like other mediaeval Christian heresies, such as those of the Paulicians and Massalians which had existed before the Bogomil movement, it was based on the dual principle of good and evil which were in constant opposition. The Bogomils preached that the world man lives in was the creation of the evil forces, and for that reason the rulers on earth – tsars, boyars, superior clergy, etc. — were servants of the devil and to fight them meant to fight Satan and to serve God. The ideal of the Bogomils was the early Christian community, such as it was described in the New Testament and they built their communes after its pattern.
Like all peasant heresies of the time, the Bogomil ideology too contained certain retrograde and utopian elements. To revive the early Christian commune was an unrealistic task, for social development had gone far ahead. This and other negative features of the movement, however, were compensated by the critical, militant charge contained in the Bogomil teaching.