By Bart D. Ehrman, The University of North Carolina, Chapel Hill
Emperor Constantine and his sons were the major part of an unusually significant dynasty in Roman history. Constantine himself served as emperor for 30 years until 337. His sons ruled for nearly 25 more years, and the dynasty continued for a total of nearly 70 years spanning most of the 4th century. How did it affect Christianity and its conversion rate?

Exponential Growth of Christianity
Constantine’s rule was an exciting time for the Christian church, as it grew by leaps and bounds with pagans converting in droves. Far more people converted in the period of this dynasty than in the entire 260 years of the church’s existence before Constantine became emperor.
However, it’s not that the rate of conversion was increasing, the rate itself had to slow down. Considering the exponential curve, the numbers snowballed even when the actual percentage decreased. By the beginning of the following century, about half of the empire would confess to the Christian faith.
Funding for Church
Constantine’s interventions on behalf of the church made it acceptable and even advantageous for members of the Roman elite to adopt the new faith. Money started flowing in from all directions as pagan cults began to shrink by attrition.

The church became so popular that there are records of fake convergence. The church father Eusebius claims that some people converted in order to take advantage of the benefactions being awarded to the church. His contemporary, Lactantius, urges church leaders to question new converts to weed out those who had been converted by coercion.
The 4th century bishop of Milan, Ambrose, mentions pagan men who allegedly converted to raise their stock with Christian women with whom they had a love interest. Even so, most of the conversions were almost certainly genuine as the church grew in numbers and power.
This article comes directly from content in the video series The Triumph of Christianity. Watch it now, on Wondrium.
Religion and Legislation
Paganism continued to thrive in the 4th century. By the 390s, the majority of the empire was still pagan and proud of it. Pagans remained in positions of power. And like most politicians today, were far more interested in the social and political issues they needed to address as officials in charge, than in their personal religious commitments or those of their colleagues and constituents.
That was true for both pagans and Christians. Their job was to run the empire not to convert the world. And the vast majority of them believed in cooperation and compromise and efficient government. Even so, some of Constantine’s successors on the throne did begin to assert their religious views and implement them in occasional legislation.
Constantine’s Most Important Contribution to Christianity
One could argue that the greatest contribution Constantine made to the Christian cause was to raise his children as Christian. That was to have an enormous effect on the course of church history over the subsequent decades. Even if rulers in the dynasty continued to do as Constantine did; commit brutal acts dictated by political expediency after his inordinately long reign.
Constantine died on May 22, 337. The events leading up to his demise are well documented. As it happened innumerable times over the course of the previous century, the empire had to deal with the problem of foreign invasions on the frontiers.
Constantine’s Baptism
Persia was beginning to flex its expansionist muscles in the east. And Constantine decided to return to the front to direct the military campaign personally. The route was to take him just to the north of Palestine and he had planned to use the occasion to be baptized in the Jordan River, just as Jesus had been three centuries earlier. But he never made it that far.
He took ill soon after the journey had begun and was forced to stop in Nicomedia in the western part of what is now Turkey. He called in the local bishop of Nicomedia, who somewhat ironically supported the theological views of Arius, the arch-villain of the Council of Nicaea. But Constantine was duly baptized, and his reign passed on to his sons.
To conclude, we can say that Christianity flourished during Constantine’s reign and continued to do so throughout the entire dynasty’s rule. Constantine’s efforts to make the Church an epitome of power bore fruits and led to a great number of conversions.
Common Questions about Christianity during Constantine’s Rule
Persia was beginning to flex its expansionist muscles in the east. And Constantine decided to return to the front to direct the military campaign personally. The route was to take him just to the north of Palestine and he had planned to use the occasion to be baptized in the Jordan River, just as Jesus had been three centuries earlier.
Constantine wanted to be baptized in Palestine. But contrary to his plans, he took ill soon after the journey had begun and was forced to stop in Nicomedia in the western part of what is now Turkey. He called in the local bishop of Nicomedia, who somewhat ironically supported the theological views of Arius, the arch-villain of the Council of Nicaea. But Constantine was duly baptized.
Constantine’s interventions on behalf of the church made it acceptable and even advantageous for members of the Roman elite to adopt the new faith. Money started flowing in from all directions as pagan cults began to shrink by attrition. The church became so popular that there are records of fake convergence.