The Roman Emperor Constantine had a decisive impact on the growth of Christianity in Europe.   One estimate puts the number of Christians as low as 3% of the population at the date of Constantine’s ascension of power.  By the time he died in 338 A.D the Empire had become Christianized to the point there was no turning back. 

Constantine’s birth date is not known but it was obviously in the last quarter of the third century A.D. His early life was spent in the army where he rose to second in command of a legion.  At that time, the Roman Empire was governed by a complex system called the Tetrarchy. The Empire was divided into four parts, each of which had a resident Emperor.  The two senior emperors were known as Augusti, and the junior emperors were known as Caesars.  The four emperors were bound together not only by Roman law and tradition, but by dynastic marriages and their sons being held hostage by other emperors.  Diocletian, the originator of the system felt it would provide stability to the Empire, as anyone wishing to control the Empire had to overthrow not one but four emperors.  Unfortunately, his plans came to naught very quickly after his retirement.

 Constantine was the son of Constantius Chlorus (the “Pale”) and Helena, a woman of very low birth. Constantius was the Caesar in the Western Empire. Constantine was stationed with the Augustus of the East, Galerius, ostensibly for training purposes but also as a hostage. Whether he was summoned by Constantius or on his own initiative, Constantine escaped from the East and made a mad dash across Europe to modern day Britain, where he arrived at his father’s court.  Constantius died soon after, and his army declares Constantine the Augustus, not the Caesar of the West in 306.  Constantius had been a very able general and tolerant of Christians.  Soldiers like effective generals and knew Constantine had already proven himself on the battlefield.

The proclamation of Constantine as Augustus threw the Empire into turmoil.   It effectively ended the Tetrarchy.  Constantine ruled Britain and Gaul, his father’s old territory.  Shortly thereafter, Spain, part of another territory (it had been joined with Italy as another imperial jurisdiction) also defected to Constantine. In 312, Constantine eliminated his enemy Maxentius, the ruler of Italy and the Roman civil diocese of Africa, at the famous battle of the Milvian Bridge. Constantine’s forces were outnumbered, and it seemed only a miracle could change the outcome of the pending battle.  A miracle may have indeed happened.  As Constantine’s forces marched towards Rome, he received a “sign”.  It is not altogether clear what this sign was, but Constantine orders the chi-rho, a Christian symbol painted on the shields of his soldiers.  Suffice it to say, Maxentius’ forces are routed, and Constantine became the sole ruler in the West.  Meanwhile, Licinius defeated another emperor in the East, and two men ruled the Empire. It seemed as if peace had finally been achieved.  Alas, this was not to be.

Licinius, who was married to Constantine’s sister, begun plotting against Constantine. Constantine marched on Licinius and by 315 takes one-half of Licinius’ territory before a truce is negotiated. Licinius is essentially forced out of Europe, resulting in Constantine controlling about three quarters of the Empire. His domain stretched from Britain to the Bosporus.  Licinius maintained control over the Roman provinces of Asia and Egypt.  This uneasy truce  lasts for a number of years until in 324 Constantine defeats Licinius in another civil war.  The Empire is once again under the rule of one man.

Constantine maintained a steady rule in the Empire.  He abolished the Praetorian Guard, long trouble makers in the imperial succession and reorganized the army. The army followed Constantine as he was an able general like his father.  Not only was he a winner in battle, but his children were as well.   Constantine believed in his own destiny, but he would not needlessly inflict casualties on his army to achieve that destiny. The fact it took Constantine almost twenty years to consolidate his power shows a remarkable patience.  

It has long been debated if Constantine was a Christian.  The following can be said about him without much controversy. Constantine followed in the footsteps of his father and stopped the persecution of Christians.  This too was an evolution as it is only after the defeat of Maxentius do Constantine and Licinius issue the Edict of Milan.  This was a watershed in Western history, as Constantine allows free worship within the Empire and the return of confiscated property to the previously persecuted Christians. He did not declare Christianity the state religion, but one could argue this would not have been politically expedient. There is no doubt he magnanimously donated wealth to the Christian Church and protected it.   Constantine was baptized on his deathbed, a widespread practice in the era.

The Eastern Church declared him a saint, an Equal to the Apostles.  Scholars have long debated that as well. He divorced his first wife, the mother of his son Crispus, because of a dynastic marriage to Fausta. Constantine eventually had Crispus and Fausta killed, and reneged on a promise to spare Licinius. Historians still debate the reasons for these executions. Yet, at the same time he abolished crucifixion as a punishment and the abandonment of babies.  In the end, all historians and scholars can agree he was an extraordinarily complex person, who did his best to keep the peace in the Empire.

Doctrinal conflicts roiled the Church and then the Empire in the early fourth century. Arianism challenged the orthodox Christian faith.  Constantine attempted to head this off with the first ecumenical council in 325.  To his credit, Constantine did not impose a solution.  He allowed the bishops of the Church to come to their own resolution.  In the end, one can suppose Constantine was only interested in a solution that would end the theological squabbling and turmoil. This attempt failed as Arianism lingered for many years in the Empire and then was forced outside of imperial territory.  Many people are astonished to hear the tribes that sacked Rome in the fifth century were in fact Arian Christians!

This summary is at best an introduction to the impact of Constantine on the world and the Church.  The following short articles provide background information on Constantine and many of the issues he had to contend with.