General Notes

Constantine the Great (about AD 274-337), Roman emperor (306-37), the first
Roman ruler to be converted to Christianity. He was the founder of
Constantinople (present-day Istanbul), which remained the capital of the
Eastern Roman (Byzantine) Empire until 1453.

Early Life
Constantine the Great was born Flavius Valerius Constantinus at Nis, in what
is now Serbia, son of the commander Constantius Chlorus (later Constantius I)
and Helena (later Saint Helena), a camp follower. Constantius became
co-emperor in 305. Constantine, who had shown military talent in the East,
joined his father in Britain in 306. He was popular with the troops, who
proclaimed him emperor when Constantius died later the same year. Over the
next two decades, however, Constantine had to fight his rivals for the throne,
and he did not finally establish himself as sole ruler until 324.
Following the example of his father and earlier 3rd-century emperors,
Constantine in his early life was a solar henotheist, believing that the Roman
sun god, Sol, was the visible manifestation of an invisible "Highest God"
(summus deus), who was the principle behind the universe. This god was thought
to be the companion of the Roman emperor. Constantine's adherence to this
faith is evident from his claim of having had a vision of the sun god in 310
while in a grove of Apollo in Gaul. In 312, on the eve of a battle against
Maxentius, his rival in Italy, Constantine is reported to have dreamed that
Christ appeared to him and told him to inscribe the first two letters of his
name (XP in Greek) on the shields of his troops. The next day he is said to
have seen a cross superimposed on the sun and the words "in this sign you will
be the victor" (usually given in Latin, in hoc signo vinces). Constantine then
defeated Maxentius at the Battle of the Milvian Bridge, near Rome. The Senate
hailed the victor as savior of the Roman people. Thus, Constantine, who had
been a pagan solar worshiper, now looked upon the Christian deity as a bringer
of victory. Persecution of the Christians was ended, and Constantine's
co-emperor, Licinius, joined him in issuing the Edict of Milan (313), which
mandated toleration of Christians in the Roman Empire. As guardian of
Constantine's favored religion, the church was then given legal rights and
large financial donations.

Sole Ruler
A struggle for power soon began between Licinius and Constantine, from which
Constantine emerged in 324 as a victorious Christian champion. Now emperor of
both East and West, he began to implement important administrative reforms.
The army was reorganized, and the separation of civil and military authority,
begun by his predecessor, Diocletian, was completed. The central government
was run by Constantine and his council, known as the sacrum consistorium. The
Senate was given back the powers that it had lost in the 3rd century, and new
gold coins (solidi) were issued, which remained the standard of exchange until
the end of the Byzantine Empire.
Constantine intervened in ecclesiastical affairs to achieve unity; he presided
over the first ecumenical council of the church at Nicaea in 325. He also
began the building of Constantinople in 326 on the site of ancient Greek
Byzantium. The city was completed in 330 (later expanded), given Roman
institutions, and beautified by ancient Greek works of art. In addition,
Constantine built churches in the Holy Land, where his mother (also a
Christian) supposedly found the True Cross on which Jesus was crucified. The
emperor was baptized shortly before his death, on May 22, 337.

Evaluation
Constantine the Great unified a tottering empire, reorganized the Roman state,
and set the stage for the final victory of Christianity at the end of the 4th
century. Many modern scholars accept the sincerity of his religious
conviction. His conversion was a gradual process; at first he probably
associated Christ with the victorious sun god. By the time of the Council of
Nicaea (325), however, he was completely Christian, but still tolerated
paganism among his subjects. Although criticized by his enemies as a proponent
of a crude and false religion, Constantine the Great strengthened the Roman
Empire and ensured its survival in the East. As the first emperor to rule in
the name of Christ, he was a major figure in the foundation of medieval
Christian Europe.