Bogomilism was a Christian neo-Gnostic or dualist sect founded in the First Bulgarian Empire by the priest Bogomil during the reign of Tsar Peter 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 with 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 what they considered to be early spiritual teaching, rejecting the ecclesiastical hierarchy, and their primary political tendencies were resistance to the state and church authorities, following the Council of Nicea or Nicene Creed. This helped the movement spread quickly in the Balkans, gradually expanding throughout the Byzantine Empire and later reaching Kievan Rus', Bosnia (Bosnian Church), Dalmatia, Serbia, Italy, and France (Cathars).
The Bogomils were dualists or Gnostics in that they believed in a world within the body and a world outside the body. They did not use the Christian cross, nor build churches, as they revered their gifted form and considered their body to be the temple. This gave rise to many forms of practice to cleanse oneself through purging, fasting, celebrating and dancing. 
The term Bogomil in free translation means "dear to God", and is a compound of the Slavic words for "god" (Common Slavic: *bogъ) and "dear" (Common Slavic: *milъ). It may be also a translation of the Greek name Theophilos, literally "dear to God; loved by the gods," from theos "god" + philos "loved, beloved". It is difficult to ascertain whether the name was taken from the reputed founder of that movement, the priest Bogomil.
The essence of Bogomilism is the duality in the creation of the world. This is why it is considered a heresy by the Catholic Church. Bogomils explained the earthly sinful corporeal life as a creation of Satan, an angel that was sent to Earth. Due to this duality, the church believes that their doctrine undervalues everything that is created with materialistic and governmental goals and further claims that the doctrine does not come from the soul, the only divine possession of the human. Its followers refused to pay taxes, to work in serfdom, or to fight in conquering wars. They ignored the feudal social system, which was interpreted by their enemies as suggesting disorder if not the destruction of the state and church.
Bogomilism in Bosnia
The late 12th century in Bosnia was a golden age for Bogomils, where it was the state religion. Despite the Bogomils suffering oppression elsewhere from the Catholic and Serbian Orthodox, Bosnia offered them safe haven. Kulin, the Great Ban (title of the local representatives of Hungarian Kings) played a very important role for Bogomils during his reign, so much that the Bogomils formed a "Bosnian Church" free from Catholic authority. This led the Bogomils to see the Ottomans as liberators and help the Turks against the Hungarians in 1414. Building closer ties with Turks, Bogomils later welcomed Ottomans when they conquered Bosnia in 1463. "Bogomils preferred to be conquered by the Sultan than converted by the Pope," said Authy Phyllis in her book "Yugoslavia". Bogomils were denounced as heretical due their doctrines, however what they endured led them later to adopt Islam, when Ottoman rule arrived the region. 
Council of Nicea
Reference from Historical Timeline Trigger Events: 1,700 YA, NAA and Luciferian Knights Templar cover story to hide the Christos Mission and humanities star origins, False Alien God worship and Blood Sacrifice based religion that became the Canonized Bible.