Diocletian and Constantine

Key Points during this time

• During a period of imperial reform in the late third and early fourth centuries, Christians underwent the most severe and widespread persecution yet.
• Though the person and motives of Constantine the Great are complex and somewhat mysterious, he achieved sole authority in the Roman Empire, ended the persecutions, favored Christianity, and ushered in Christendom.
• The church was largely unprepared for the many challenges accompanying the change in church-state relations.
• The Donatist controversy exem
  plified the way in which state involvement could affect church affairs, as rigorist and laxist factions faced off in North Africa and experienced the impact of imperial intervention.
• Many bishops met in the first ecumenical council at Nicaea in 325 to debate the theological views of the subordinationist Arius, resulting in the Nicene Creed and signaling new developments in the ways church and state leaders would tackle issues affecting Christianity at large in the Roman Empire.

Summary
When Diocletian became emperor in 284, he undertook a reorganization of the empire, establishing a new provincial map and distributing power through a tetrarchy. His colleague Galerian instigated the “Great Persecution” of Christians, the most systematic persecution yet, culminating in an edict requiring that all sacrifice to the gods or suffer severe penalty.

After a period of civil war and continued internal strife, Constantine the Great emerged as the sole ruler of the Roman Empire. His mother Helena had been a Christian, and Constantine began to favor Christianity in his reunified empire. Various theories seek to explain Constantine’s motivations, with perhaps the most likely being those that correlate his personal piety with his desire to have concord in the empire—under his solitary and God-given reign. In any case, the persecutions stopped and Christians began to be favored in a variety ways by the state, inaugurating an era of Christendom for which the church was not especially well prepared. Constantine sponsored grand Christian building projects and got involved in church affairs, including the Donatist schism of North Africa. In Carthage, tensions between laxist and rigorist groups, exacerbated by personal issues, came to a head in the contested election of the bishop, resulting in the emperor’s intervention by means of the Synod of Arles (314), the first church council called by an emperor. The synod found in favor of the more laxist party, causing their rigorist Donatist opponents to fracture away from the catholic church and form a schism that was actually a majority force in some parts of the North African church—a schism very suspicious of Christendom.

More far-reaching was the Council of Nicaea (325), also called by the emperor as part of his strategy to find and maintain unity in church and empire. Although political rivalries between the churches in Antioch and Alexandria fueled the controversy leading to this council, the presenting problem had to do with the teaching of the subordinationist Arius in Alexandria, who taught that “there was (once) when Christ was not.” Various perspectives met to discuss the matter at Nicaea, the majority being suspicious of new formulae, wanting to preserve unity, and desiring to defend monotheism and the divinity of Christ. Therefore, Arius and his supporters were condemned, and a creed was prepared using the term, homoousios, by which the council sought to preserve the belief that God the Father and God the Son shared the “same substance.” Despite the council’s decisions, the creed, and the emperor’s backing, the politics of the emerging new situation ensured that the controversy would continue to gain traction through much of the rest of the fourth century.

As the first “ecumenical council,” Nicaea marked a shift in the way the church discussed and enforced decisions about doctrinal matters that were central to the church everywhere. It is symbolic of imperial involvement in church affairs, and it also marked an important development in doctrinal history, through its enforcement of the creed with anathemas for any who would reject it.