(c. 274—337) Roman emperor
‘the Great’ (c. ad 272/3–337), b. in the Balkan province of Moesia, was son of Constantius I and Helena. When Constantius, now senior Augustus, died at Eburacum (306), his troops proclaimed Constantine Augustus. Only after 20 years of struggle did Constantine emerge as sole Augustus.
In November 324 Constantine founded Constantinople on the site of Byzantium. The need for an imperial headquarters near the eastern and Danubian frontiers had been seen by Diocletian. The city's dedication with both pagan rites and Christian ceremonies took place in May 330. From the beginning it was ‘New Rome’, though lower in rank. Many traditional features of Rome (not temples and cults) were in time reproduced. To speak of the foundation of a capital is misleading; yet a permanent imperial residence in the east did in the end emphasize division between the empire's Greek and Latin parts.
In a reunited empire Constantine was able to complete Diocletian's reforms and introduce innovations. The separation of civil and military commands was completed. A substantial field army was created under new commanders responsible directly to the emperor: its soldiers had higher pay and privileges than the frontier troops. Constantine radically reorganized the government. He tried vainly to stop corruption in the steadily growing bureaucracy. He gave senatorial rank freely, and reopened many civilian posts to senators, who began to recover some of their lost political influence. From his reign survive the first laws to prevent tenant farmers and other productive workers from leaving their homes and work. His open‐handedness harmed the economy: taxation (mostly in kind) rose inexorably despite the confiscation of the vast temple treasures. He established a gold coinage, but the other coinage continued to depreciate.
Resident now in the more Christianized east, his promotion of the new religion became clearer. He openly rejected paganism, though without persecuting pagans, favoured Christians as officials, and welcomed bishops at court, but his actions in Church matters were his own. He now confronted another dispute which was rending Christianity, the theological questions about the nature of Christ raised by Arius. To secure unity Constantine summoned the council which met at Nicaea in 325 (later ranked as the First Ecumenical Council), and proposed the formula which all had to accept. Dissidents were bludgeoned into agreement; but Athanasius' view that his opponents had put an unorthodox interpretation on the formula was seen by Constantine as vexatious interference with attempts to secure unity. Even if his success in this aspect was superficial, he nevertheless brought Christianity from a persecuted minority sect to near‐supremacy in the religious life of the empire.
He spent the generally peaceful last dozen years of his reign in the east or on the Danube, though he visited Italy and Rome, and campaigned on the Rhine. Victory over the Goths was followed by a campaign against the Sarmatians, many thousands of whom were then admitted within the empire as potential recruits. In 336 he fought north of the Danube, even recovering part of Dacia. The empire's prestige seemed fully restored; a Persian war loomed but did not break out until after his death. Baptized when death approached (such postponement was common at the time), he died near Nicomedia in Bithynia (May 337).