The Bogomils likely originated between 927 and 969 as a reactionary group against the oppression from the political and clerical authority figures. Scholars credit Bogomilism as the first significant heretical sect in Bulgarian history.
In 863 CE, Khan Boris I legalized the forced Christianization of the Slavs and proto-Bulgarians. At this time in history, all church services were orated in Greek, a language only known by the educated upper class. This resulted in a one-dimensional understanding of the Christian religion. The newly converted Christians not only forcibly attended services, but they could not fully comprehend the religion that they were forced to subscribe to.
Additionally, the hangover from wars fought in Thrace left many villages destroyed and many peasants jobless. The lower classes were further antagonized by being forced to pay higher taxes. Many of these people attempted to find assuagement in the Church, but were unsuccessful.
The presence of Manichaeism and Paulicianism provided the necessary foundation for the unification of the unhappy lower classes. Basing a newfound religious belief system upon the dualist beliefs of these other alleged heresies, Bogomilism acted as an umbrella under which these people could worship.