“Christianity transformed from a persecuted, unorganized group of believers into a hierarchical, dominating Church over the course of seven centuries, developing alongside the changing political environment of post-Roman Europe. The development of the institution of the Catholic Church and the spread of Christ throughout Europe during these seven centuries directly impacted every aspect of late-antiquity and early-medieval life, especially politics and the relationship between kings and religion. During this time period the Church rejected its domination by the Roman and Byzantine emperors, in turn exerting its own type of spiritual dominance over the rulers of post-Roman Europe. Christianity, through the Church, became organized and “conquered” all of Europe by the time of the Norman Conquest of England in 1066.
Christianity had developed as a religious idea in Roman Palestine, and had slowly spread throughout the eastern part of the Empire toward the west. During the first three centuries of its existence, Christianity remained disorganized and concentrated within the cities. Each group of believers centered around a few charismatic local leaders and developed their own liturgy. However, the conversion of Emperor Constantine in AD312 changed the structure of Christianity and turned it into a well-organized, quasi-political institution. The Church provided Constantine with a tool to use to hold together the crumbling Empire. The Church came under the Emperor’s control with the Emperor as the divus caesar, or divine emperor. Constantine used the Christian bishops as imperial officials to administer law and justice throughout the Empire. These “imperial bishops” answered directly to the Emperor, thus instituting imperial dominance over the Church. The Council of Nicaea in AD325 further brought the Church under imperial control with the establishment of a uniform liturgy to use throughout the Empire and approved by the Emperor. Imperial dominance was completed with Theodosius II proclaiming Christianity to be the official religion of the Roman Empire a century later. Thus began the period of praeparatio evangelii, the Christian conquering of the world.”