Bogomilism was dualistic in nature -- that is, its followers believed that both good and evil forces created the universe. Bogomils believed that the material world was created by the devil, and they therefore condemned all activities that brought mankind into close contact with matter, including eating meat, drinking wine, and marriage. Bogomils were noted and even praised by their enemies for their austerity, but their rejection of the entire organization of the Orthodox Church made them heretics, and they were therefore sought out for conversion and, in some cases, persecution.
Bogomilism spread over much of the Byzantine Empire during the 11th and 12th centuries. Its popularity in Constantinople resulted in the imprisonment of many prominent Bogomils and the burning of their leader, Basil, in about 1100. The heresy continued to spread, until by the early 13th century there was a network of Bogomils and followers of similar philosophies, including Paulicians and Cathari, that stretched from the Black Sea to the Atlantic Ocean.
In the 13th and 14th centuries, several delegations of Franciscan missionaries were sent to convert heretics in the Balkans, including Bogomils; those they failed to convert were expelled from the region. Still Bogomilism remained strong in Bulgaria until the 15th century, when the Ottomans conquered parts of southeastern Europe and the sects began to dissipate. Remnants of dualistic practices can be found in the folklore of southern Slavs, but little else remains of the once-powerful sect.
The Bogomils may have been the connecting link between heretical sects of the East and the West.
Bogomilism included Dualistic tenets.