History of Christianity

===Influence of Constantine in Late Antiquity===
{{Main|Constantine the Great and Christianity}}
{{Further|Historiography of Christianization of the Roman Empire|Religious policies of Constantine the Great}}
[[File:Nicaea icon.jpg|thumb|Icon depicting the [[Constantine I|Emperor Constantine]] (centre) and the [[bishop]]s of the [[First Council of Nicaea]] (325) holding the [[Nicene Creed#Niceno-Constantinopolitan Creed|Niceno–Constantinopolitan Creed of 381]]|alt=this is a photo of an old eastern icon depicting the Emperor Constantine in the center and a few bishops holding the Nicene Creed in front of them]]
The Roman Emperor [[Constantine I (emperor)|Constantine the Great]] became the emperor in the West and the first Christian emperor in 313. He became sole emperor when he defeated [[Licinius]], the emperor in the East, in 324.{{sfn|Cameron|2006b|p=542}} In 313, Constantine issued the [[Edict of Milan]], expressing tolerance for all religions, thereby legalizing Christian worship.{{sfn|Cameron|2006b|p=542}} Christianity did not become the official religion of the empire under Constantine, but the steps he took to support and protect it were vitally important in the history of Christianity.{{sfn|Cameron|2006b|pp=538, 544}}

Constantine established equal footing for Christian clergy by granting them the same immunities polytheistic priests had long enjoyed.{{sfn|Cameron|2006b|pp=538, 544}} He gave bishops judicial power.{{sfn|Cameron|2006b|p=546}} By intervening in church disputes, he initiated a precedent.{{sfn|Gerberding|Moran_Cruz|2004|pp=55–56}}{{sfn|Cameron|2006b|p=545|ps=: "In one of the most momentous precedents of his reign, during Constantine’s twentieth anniversary celebrations in 325, some 250 bishops assembled at Nicaea in the emperor’s presence and at his order to settle difficult issues of contention across the empire about the date of Easter, episcopal succession and Christology. Constantine made a point of deferring to the bishops. He did not preside himself and only took his seat when they did, but it was the emperor who had summoned the council, and the sanctions that followed for the small number of dissenters including Arius were also imposed by him."}} He wrote laws that favored Christianity,{{sfn|Southern|2015|p=455–457}}{{sfn|Gerberding|Moran_Cruz|2004|pp=55–56}} and he personally endowed Christians with gifts of money, land and government positions.{{sfn|Bayliss|2004|p=243}}{{sfn|Leithart|2010|p=302}} Instead of rejecting state authority, bishops were grateful, and this change in attitude proved to be critical to the further growth of the Church.{{sfn|Cameron|2006b|p=546}}

Constantine's church building was influential in the spread of Christianity.{{sfn|Cameron|2006b|p=546}} He devoted imperial and public funds, endowed his churches with wealth and lands, and provided revenue for their clergy and upkeep.{{sfn|Cameron|2006b|p=547}} This led to similar efforts on a local level, leading to the presence of churches in essentially all Roman cities by the late fourth century.{{sfn|Cameron|2006b|p=547}}