I (288?-337)

The Roman emperor who allowed freedom of worship in the empire, thus ending the persecution of Christians. Flavius Valerius Constantinus (Constantine) was born to Constantius Chlorus and Helena. When his father was appointed Caesar in 293, was sent to the court of DIOCLETIAN, the senior emperor, where he later distinguished himself as a military officer in the campaigns of Galerius against Persia. When Constantius died at York on 25 June 306, Constantine, who was with his father at the time, was proclaimed Augustus by the troops. On 28 October 312 he became senior ruler of the empire when he defeated his rival, Maxentius, at Rome’s Milvian Bridge.

The events at the Milvian Bridge that presaged Constantine’s victory have been the subject of much debate and various interpretations. Lactantius, writing shortly after the event, stated that was told in a dream to have the heavenly sign of God placed on the shields of his soldiers. In accordance with this admonition, he denoted Christ on the shields by inscribing on them an X with the upper arm bent over.

Eusebius relates in his Life of Constantine (1.26-40) that on the eve of the battle against Maxentius, Constantine, convinced that he would need the aid of some supernatural power to prevail in the conflict, pondered which god he should supplicate. Recalling that the emperors before him had placed their hopes in a multitude of gods and had suffered heaven-sent catastrophes, he resolved to trust in the one Supreme God of his father. He then prayed and begged this God to reveal who he was and to stand by him in his present difficulties. While was thus beseeching God, he and his army saw in the afternoon sky the cross of Christ, consisting of light, and the legend “By this, conquer.”

That night, after had fallen asleep while puzzling over the meaning of this epithet, Jesus Christ appeared before him with the sign that had shone in the sky and commanded him to use a likeness of the sign as protection in his encounters with the enemy. Accordingly, Constantine had workers in gold and precious stones construct a replica of the sign. The result was a gilded spear with a transverse bar topped with jewels encircling the monogram of Christ (the chi- rho symbol). summoned to his camp Christian teachers, by whom he was instructed in the teachings and doctrines of the God who had appeared to him.

Scholars have debated, and continue to do so at great length, what actually experienced at the Milvian Bridge. They disagree also about the appearance and possible pre-Christian significance of the sign that Constantine inscribed on his shields, or at least carried into battle. But what is clear is that Constantine acted as if he had experienced a life-changing event, and shortly thereafter he became a devoted supporter of the beleaguered Christian religion.

Early in 313, met in Milan with Licinius, his fellow Augustus. They formed an alliance, sealed it with the marriage of Constantine’s half-sister, Constantia, to Licinius, and issued the decree now known as the Edict of Milan. The major thrust of the edict was to allow freedom of worship to all inhabitants of the empire and specifically to halt all persecution of Christians, as well as to restore to the church properties confiscated in earlier persecutions.

However, prohibitions against persecution from without could not guarantee peace within the church. soon found himself embroiled in the Donatist controversy, which erupted over the discipline of those who allegedly betrayed the faith during the Great Persecution under Diocletian in 303 and was destined to rack the church in North Africa for almost four centuries (see DONATISM). Though his extended and patient efforts to arbitrate the issue fairly and to establish peace between the rival factions met with failure, Constantine’s response to the controversy evinced his genuine concern for the well-being of the church.

When the Numidian bishops communicated to their contention that Caecilius’ consecration as bishop of Carthage was invalid and that Constantine’s support of the Caecilian clergy was partial and unwarranted and asked the emperor to draw up a committee of Gallic judges to decide the issue, Constantine remanded the case to the bishop of Rome, who enlisted the aid of three Gallic and ten Italian bishops. The case was heard on 2-5 October 313, and the judgment went against the Numidian faction, which had become known as Donatist, after its leader Donatus. When the Donatists appealed the decision to Constantine, the emperor once again displayed his concern for the welfare and unity of the church by convening another hearing at Arles on 1 August 314.

This council confirmed the verdict of the Council of Rome. conducted his own investigation into the validity of Caecilius’ consecration, and on 10 November 316 he endorsed Caecilius as bishop of Carthage and denounced the Donatists, whom he had come to see as heretics and schismatics. However, as evidenced by the fact that “heretical” Donatism remained the dominant form of Christianity in North Africa for many decades thereafter, Constantine’s final verdict did nothing to heal the rift.

During the controversy the peace between and Licinius had begun to sour, eventually breaking down completely in 324. Licinius in the east violated not only the spirit of the Edict of Milan but also its specific prohibition against the persecution of Christians. He expelled Christians from his court, outlawed bishops’ councils, ruled that Christian men and women could not worship together in churches, and forbade meetings of Christians within the cities.

There is also some evidence that Christians were martyred in the east with Licinius’ compliance. Such measures and events must have been galling to Constantine, who openly supported Christianity in the western part of the empire with legislation, building programs, and an occasional special dispensation for Christian concerns. In 321 and again in 322, in an act that must have been calculated to rile his eastern counterpart, appointed consuls of his own choosing without the approval of Licinius.

Then in 323, crossed into the territory of Licinius while chasing back invading Goths, who had caused much destruction in Moesia and Thrace. When Licinius’ protests won him no satisfaction, war broke out between the two emperors. On 18 September 324, Licinius was defeated at Chrysopolis. Constantine spared his life, sending him to Thessalonica, but Licinius died or was executed—accounts vary— not long afterward. Some said he died in a soldier’s brawl, others that he was found to be plotting against Constantine, who executed him for his perfidy, and there is some conjecture that Constantine, without any provocation except the constant fear of an eventual uprising, had him put to death.

Not long after the death of Licinius, Constantine’s attention was drawn to the controversy brewing in the east between ALEXANDER I and ARIUS. Under the direction of Alexander, a council of some one hundred bishops anathematized Arius for teaching that the Son of God was posterior to the Father, was created by the Father, and therefore was not God in the same sense as the Father. Arius appealed to his friend Eusebius, bishop of Nicomedia, for aid. Eusebius responded by providing refuge for Arius and convoking a synod of bishops of Bithynia, which approved Arius and his teachings.

wrote a letter to Alexander and Arius, urging them to put aside their differences and to come together in a unity of the faith. The letter is an indication of Constantine’s desire for peace and tranquillity within the church, but it betrays his ignorance of the gravity of the doctrine over which the two parties were divided. Theirs was not a petty squabble over a trifling matter, as Constantine suggested. It was a major rift on an issue that was at the very heart of Christian theology and was destined to split the church.

When it was apparent that a mere letter would not suffice to quell the controversy, invited the bishops to convene in an ecumenical council at Nicaea, in Bithynia, in June 325. Socrates related that the emperor brought to the council a number of petitions addressed to him by various bishops accusing other bishops of heresy or political intrigue. Constantine burned these petitions in front of all assembled with an oath that none of them had been read and with the admonition that “Christ bids him who hopes for forgiveness forgive an erring brother.” Such magnanimity, however, did not prevail at the council.

Nonetheless, the council was able to agree on a statement of belief, the NICENE CREED. EUSEBIUS OF CAESAREA explained that when the first draft of the creed had been drawn up, urged all to accept it after the word “consubstantial” (see HOMOOUSION) was added to the description of the Son’s relationship with the Father (Socrates Historia Ecclesiastica 1.8). Apparently he was concerned that the wording was capable of an Arian interpretation. The motion was carried. The council anathematized Arius and his teachings. naively believed he had squelched the Arian heresy and restored unity to the church.

Arius was reinstated in the church at a subsequent council in Nicaea in 327, but ATHANASIUS, who had succeeded Alexander as patriarch of Alexandria, refused to readmit him to the Alexandrian see, despite Constantine’s urging. Arius’ supporters, working through the MELITIANS, attempted to discredit Athanasius and to drive him from his bishopric. Their deceptive efforts not only came to naught but also were discovered to be fraudulent, and Constantine, now convinced that Arius’ repentance and return to orthodoxy had not been sincere, issued an edict that all Arian literature was to be burned and that anyone who concealed Arian texts should be put to death.

Still, the persecution of Athanasius by his Melitian and Arian foes continued. Among other things, Athanasius was accused of acquiring his office illegitimately, of ravishing a virgin, and of killing a Melitian bishop to use his body for sorcery. When Athanasius’ supporters went out and found the man alive, his detractors said he was using wizardry to fool men’s eyes.

Constantine, influenced, no doubt, by pro-Arians who had access to the imperial court, such as Eusebius of Nicomedia and his own sister, Constantia, scheduled a council at Tyre in 335 at which Athanasius should defend himself from the charges. However, when it became apparent to Athanasius that the council was dominated by those with pro-Arian sympathies and that his own supporters had been locked out, he fled to Constantinople. But charges were soon brought against him that he had threatened to cut off the vital grain supply from Egypt to Constantinople, and banished him immediately to Trier, where he remained until after the death of the emperor in 337.

appears to have vacillated wildly in his treatment of both Arius and Athanasius. This ambivalence is probably to be explained partly by his want of deep understanding of the theological questions at issue and partly by his zeal to mend the church and make it whole again in the easiest and quickest way possible.

In addition to his conversion to, and support of, Christianity, also left his mark on the empire by founding the city of Constantinople. Following the example of Diocletian, who had made moves to establish an eastern capital in Nicomedia, Constantine established Constantinople, the “New Rome,” on the site of Byzantium. The geographical position of the old city was well suited to serve as the base for the much-needed imperial presence in the eastern portion of the empire and for a military bulwark against the incursions of eastern nomads such as the Scythians, Goths, and Sarmatae. Constantine maintained throughout his life that he had built the city in obedience to God’s command.

Tradition states that when was marking off the boundaries for the city’s walls, one of his advisers, alarmed at how far afield the emperor was tracing the line, expressed concern to his ruler. Constantine replied that he would continue forward until the invisible guide marching before him thought it right to stop. Work on the new capital was begun in 326, and formal dedication rites were held in May 330. The city included many of the features of Rome, such as the Senate, but the predominant influence throughout was Christian; the pagan temples and shrines of the old capital were not to be found in Constantinople.

died on 22 May 337.


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  • Barnes, T. D. and Eusebius. Cambridge, Mass., 1981. Baynes, N. H. Constantine the Great and the Christian Church, 2nd 1972. Oxford, 1972.
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  • Amsterdam, 1981; includes English translation of documents relevant to the major events in Constantine’s life.