In 313 A.D., Constantine and Licinius issued an edict of tolerance in Milan, putting the Christian religion on equal footing with existing Roman cults. Less than a century later, Christianity would become the state religion of Rome. Constantine was the first to use it as an instrument to strengthen his rule, subjecting the Church to strict political control, a practice followed bv his successors. The de facto division of the empire into a Western (Roman) and Eastern (Byzantine) became permanent in 395. While the Roman Empire declined, Byzantium rose as a new power in its own right.
 

Constantine the Great
 

In 324 Constantine was able to establish sole rule and reorganize the empire. He encouraged Christianity in all areas.
 

Following the 5 victory over their opponents in 313, 1 Constantine and Licinius divided the empire between them and issued the Edict of Milan, which guaranteed 2 Christians the right to practice their religion.

Cooperation between the two did not last long, however. From 316 on, military clashes between the adversaries took place. Constantino ultimately triumphed and exiled Licinius.

Constantine increasingly saw himself as the representative of the Christian god and protector of Christianity. He clearly recognized the potential of the new religion and wanted to tic it into the Roman ideology of the state.

He reimbursed the Church for confiscated property and financed the construction of 4, 6 churches.

However, the 3 "Donation of Constantine" of state-owned land to the church is a myth resulting from a document forged around 850.

Constantine implemented many new laws that were influenced by Christian standards. He repealed punishment such as gladiatorial service, maiming, and limited slavery and passed relatively progressive marriage and family laws. By emphasizing the divine right of kings, he reinforced the role of religious legitimacy in imperial rule. Any offense against a Christian emperor became sacrilege toward God and God's order. The emperor not only intervened in Church politics, but also had the final say concerning matters of faith. Many Christians began to identify with the empire that had previously persecuted them and sought to participate in its affairs. The Church adopted many organizations and state offices into its own structures.

3 The Donation of Constantine, fresco, 1246

Constantine's Successors

A fratricidal war destabilized the empire after Constantine's death. Ultimately Constantius II was able to continue his father's policies successfully. The attempt of Julian the Apostate to revert to paganism remained an aberration.
 

In 330 Constantine renamed the city of Byzantium 11 Constantinople as the new capital of the Roman-Christian empire.


11 Constantine founds Byzantium's new capital
under the name Constantinople in 330


By 335 he had instituted a system of imperial succession influenced by Diocletian's tetrarchy: His oldest and second sons, Constantine II and Constantius II, were to be augusti, while his youngest son Constans and his nephew Dalmatius would be caesars. However, when Constantine died in 337 in the initial stages of a planned military excursion to Persia, a few days after he had accepted a Christian 7 baptism, all three of his sons assumed the title of augustus.


7 Baptism of Constantine the Great by Pope Sylvester I,
fresco. 1246

A murderous fratricidal war flared up, during which 10 Constantius II, son of his father's first wife Fausta, had all his relatives by his father's second marriage killed.

Out of the struggle for power he emerged triumphant. After he had repulsed the attacking Persians, he actively continued his father's church policies. Because the quarrel over Arianism and other early splinter groups of Christianity threatened to destabilize the empire, Constantius attempted to foster politico-religious unity by particularly emphasizing the overarching position of the Christian emperor. His court ceremonies already bore the features of the ruler's religious zeal that were later characteristic of the son Byzantine Empire.

Constantius's successor in 361 was his cousin 8, 9 Julian, who had held the office of caesar of the West since 355 and had assumed the title of augustus against Constantius in 360. The philosophical and highly educated Julian is one of the tragic figures of late antiquity. Due to his enthusiasm for Greek philosophy and the greatness of ancient Rome, he lost his faith, reverted to paganism and attempted to suppress Christianity and install a neo-Platonic sun cult. He did not persecute the Christians, but his attempt to turn back time led to unrest in the empire. When he fell in battle against the Persians in June 363, his new sun cult broke up and the Christian historians damned him as "the Apostate." His death marked the end of rule by Constantine's dynasty.
 

Arianism

Encyclopaedia Britannica

Christian heresy

A Christian heresy first proposed early in the 4th century by the Alexandrian presbyter Arius. It affirmed that Christ is not truly divine but a created being. Arius’ basic premise was the uniqueness of God, who is alone self-existent and immutable; the Son, who is not self-existent, cannot be God. Because the Godhead is unique, it cannot be shared or communicated, so the Son cannot be God. Because the Godhead is immutable, the Son, who is mutable, being represented in the Gospels as subject to growth and change, cannot be God. The Son must, therefore, be deemed a creature who has been called into existence out of nothing and has had a beginning. Moreover, the Son can have no direct knowledge of the Father since the Son is finite and of a different order of existence.

According to its opponents, especially the bishop Athanasius, Arius’ teaching reduced the Son to a demigod, reintroduced polytheism (since worship of the Son was not abandoned), and undermined the Christian concept of redemption since only he who was truly God could be deemed to have reconciled man to the Godhead.

The controversy seemed to have been brought to an end by the Council of Nicaea (ad 325), which condemned Arius and his teaching and issued a creed to safeguard orthodox Christian belief. This creed states that the Son is homoousion tō Patri (“of one substance with the Father”), thus declaring him to be all that the Father is: he is completely divine. In fact, however, this was only the beginning of a long-protracted dispute.

From 325 to 337, when the emperor Constantine died, the Arian leaders, exiled after the Council of Nicaea, tried by intrigue to return to their churches and sees and to banish their enemies. They were partly successful.

From 337 to 350 Constans, sympathetic to the orthodox Christians, was emperor in the West, and Constantius II, sympathetic to the Arians, was emperor in the East. At a church council held at Antioch (341), an affirmation of faith that omitted the homoousion clause was issued. Another church council was held at Sardica (modern Sofia) in 342, but little was achieved by either council.

In 350 Constantius became sole ruler of the empire, and under his leadership the Nicene party (orthodox Christians) was largely crushed. The extreme Arians then declared that the Son was “unlike” (anomoios) the Father. These anomoeans succeeded in having their views endorsed at Sirmium in 357, but their extremism stimulated the moderates, who asserted that the Son was “of similar substance” (homoiousios) with the Father. Constantius at first supported these homoiousians but soon transferred his support to the homoeans, led by Acacius, who affirmed that the Son was “like” (homoios) the Father. Their views were approved in 360 at Constantinople, where all previous creeds were rejected, the term ousia (“substance,” or “stuff”) was repudiated, and a statement of faith was issued stating that the Son was “like the Father who begot him.”

After Constantius’ death (361), the orthodox Christian majority in the West consolidated its position. The persecution of orthodox Christians conducted by the (Arian) emperor Valens (364–378) in the East and the success of the teaching of Basil the Great of Caesarea, Gregory of Nyssa, and Gregory of Nazianzus led the homoiousian majority in the East to realize its fundamental agreement with the Nicene party. When the emperors Gratian (367–383) and Theodosius I (379–395) took up the defense of orthodoxy, Arianism collapsed. In 381 the second ecumenical council met at Constantinople. Arianism was proscribed, and a statement of faith, the Nicene Creed, was approved.

Although this ended the heresy in the empire, Arianism continued among some of the Germanic tribes to the end of the 7th century. In modern times some Unitarians are virtually Arians in that they are unwilling either to reduce Christ to a mere human being or to attribute to him a divine nature identical with that of the Father. The Christology of Jehovah’s Witnesses, also, is a form of Arianism; they regard Arius as a forerunner of Charles Taze Russell, the founder of their movement.

 

Ceiling Mosaic of the Arian Baptistry