Codex Vaticanus is transcribed and becomes one of the “oldest extant” manuscripts of the Bible. 

Diocletian retires from the empire.

Constantine I, soon to be known as “Constantine the Great,” is proclaimed as the Roman Emperor at age 34 by the military who supported his single rule over the western empire.

The Roman Empire is without an official leader because of dissention regarding Constantine and the other Caesars.

Constantine I is made official Augustus over the Western Roman Empire.

Licinius forms an alliance with the west through a marriage to Constantine’s sister, Flavia Julia Constantia.

Edict of Milan is issued as an agreement between Constantine (of the western Roman empire) and Licinius (of the eastern Roman empire) to end persecution of Christian believers.  Thus, the Roman Empire (future Byzantine Empire) would become neutral on matters of religion.

St. Alexander, the archbishop of Alexandria, calls a council meeting to condemn the divisive and increasingly popular message of Arianism (see 325 AD).

Licinius goes against the Edict of Milan and begins another persecution of Christians and thus begins the footsteps of pre-civil war between east and west.

Eusebius of Caesarea writes his famed Ecclesiastical History in which he compiles the Hexapla, Melito, and Muratorian Fragments together and draws several conclusions about the possibility of a widespread canon. In his "history," Paul is ascribed as the author of the Epistle to the Hebrews and the Epistles of James and Jude are deemed an unsettling inclusion to the canon of Scripture.

Western and Eastern Roman Empire enter into a civil war because of Constantine's protection of Christianity and Licinius' efforts to persecute believers. During this war, Licinius is assassinated by Constantine's military.

First Council of Nicea commences as the first meeting of bishops and church leaders to address doctrinal and practical matters of Christian faith.  Constantine signals an imperialistic presiding at the council so that a certain level of control can be maintained over the church.

The Nicene Creed is written and accepted as a widespread Christian “statement of faith.” 

Eusebius, who is now the Bishop of Palestine, creates a confession that quickly becomes the basis for the Nicene Creed.  

Constantine executes his son and wife upon the allegations that there had been an affair between them. This execution had been so unexpected on the journey to Rome that upon arrival, he left quickly to re-establish a new center of the empire.

After having a horrible experience on his way to Rome in 326 AD, Constantine's Nova Roma (New Rome) was dedicated as Constantinople. From this point, the Eastern Roman Empire was to be called the Byzantine Empire.

Julian, the future emperor of Rome (361 AD), is educated and trained by Eusebius of Nicomedia, a firm believer in arianism.

Constantine dies without entrusting his empire to his sons. The Byzantine Empire continues to go on under the reign of Constantine until Constantine II was chosen by the military to take over the throne.

Jerome, the author of the Latin Vulgate, is born.

Development of the Arabic Alphabet begins.

The Codex Sinaiticus, or oldest known Greek bound volume of pages is written.

Cyril of Jerusalem writes a canon list that excludes John's Book of Revelation because of how it had been allegedly overused or exaggerated by the Monanists of the day.

Julian the Apostate meets with Gregory of Nazianzus, but begins to push Christian influences away in his attraction to pagan lectures and teachers.

Hilary, the Bishop of Poitiers, compiles a Hebrew canon that's based on the notion of only a twenty-two book testament. This concept was built around the Hebrew alphabet, which consisted only of twenty-two letters. In his Hebrew canon, Hilary indicates that there are some who add Judith and Tobit to equal a twenty-four book testament equivalent to the twenty-four letters of the Greek alphabet.

The Cheltenham List is compiled as the full Old and New Testament canon.

Julian the Apostate becomes emperor of Rome. His background and early development led him to reject Christianity because he believed it had been forced on him. This rejection becomes known to Christians as a title "apostate."

Emperor Julian guarantees freedom of religion to all in the Roman Empire.

The Council of Laodicea meets to address the Biblical canon of Scripture.

Emperor Julian dies and is succeeded by the short-lived emperor Jovian. Jovian's reign would signify a nearly 100 year period of decline in an empire that appeared to be on the verge of extinction.

Athanasius of Alexandria becomes the first to compile the 27-book New Testament that is familiar to most modern Christians.

Gregory of Nazianzus, in his own canon (excluding Revelation), makes the statement implying that Matthew's gospel was written to the Hebrews while Mark wrote to Italy and Luke to Greece.

The Biblical canon of Athanasius is accepted in the west at the Synod of Rome.

Due to the Theodosian Decrees, the Nag Hammadi Library is formed as an equivalent term to the gnostic gospels. In the expelling of gnostic texts, all were hidden in this library until their discovery in 1948.

The Synod of Carthage-Hippo meets to formally accept the present canon throughout all the church. St. Augustine attends the meeting.