“With such impiety pervading the human race, and the Senate threatened with destruction, what relief did God devise?…I myself was the instrument he chose…Thus, beginning at the remote Ocean of Britain, where the sun sinksbeneath the horizon in obedience to the law of Nature, with God’s help I banished and eliminated every form of evil then prevailing, in the hope that the human race, enlightened through me, might be recalled to a proper observence of God’s holy laws.” -Emperor Constantine the Great. (a quote from Eusebius that appears in John Julius Norwich’s Byzantium: The Early Centuries).
Background: Emerging from the Crisis of the Third Century
In the opinion of 20th century historian George Ostrogorsky “the beginning of Byzantine history can be traced back to the Roman Empire as it emerged from the crisis of the third century (Ostrogorsky, pg. 29).” The Roman Empire nearly collapsed during this time, splitting into the three warring factions in a chaotic period that lasted from 235–284 AD (see map above). This period seriously disrupted the Roman economy, but this was far more pronounced in the Western half of the Empire. The East did suffer, but it retained it’s population levels and a higher level urbanization than much of the West did.
When the Roman Empire was reunited by Aurelian in 275 under the rule of one Emperor, it did not last long. Chaos lasted until 284 when Diocletian took power and immediately implanted massive reforms. He divided the Empire into four regions ruled by four Emperors, and created a vast civil bureaucracy which was to be a defining feature of the Byzantine state. Ostrogorsky wrote that “the important reforms of Diocletian were designed to meet the new situation which had been created during the disturbances of the third century. He used what was of value from the earlier system, but accepted or introduced necessary changes, so that the result of his work was a fundamental reorganization of the whole imperial administration. Constantine the Great was responsible for the further development and completion of Diocletian’s work. Thus a new system grew up which was to be the basis of Byzantine administration (Ostrogorsky, pg. 33).”
Origins:
Constantine was born in Naissus (modern Nis), in the province of Dacia, most likely in 274AD. He was the son of Constantius Chlorus, a successful Roman general, and a Greek woman named Helena from Bithynia. Constantius Chlorus eventually became one of the Tetrarchs, the four rulers who governed the Roman Empire in the system set up by Diocoletian. Rome had not been a strategic center of the Empire for some time by this point. Diocletian ruled from Nicomedia, Maximian from Milan, Galerius in Thessalonika, and Constantius Chlorus ruled from Trier.
This system set up by Diocletian was doomed to fail with him to hold it in place. The idea that the Empire could have four rulers and remain a unified state seems impossible to have believed. Constantine spent much of his youth in Diocletian’s court, giving him a good idea on how to wield power. It was probably he was a hostage to ensure Constantius Chlorus did not go rogue. Constantine gained valuable experience during this time, going on campaigns to Egypt and in wars against the Persians. He met the young Eusebius in Palestine en route to Egypt, a Christian scholar who would play a huge role in the story of Constantine later on.
Foundation of Constantinople:
THE BYZANTINE WORLD VIEW IN EUSEBIUS OF CAESAREA:
It is from the time of Constantine that the Byzantine’s got their world view. This view would be, at least symbolically, true throughout the entirety of Byzantine history. In this ideology, Christianity and imperial rule are a tandem administration of both the heavens and the earthly realm respectively. Even later Emperors ruling over a sliver of what Constantine did would identify with this worldview, where the Emperor was head of the Church and head of the state.
The historian Eusebius of Caesarea wrote an oration in lavish and elongated praise of Constantine, delivered in 335AD. In it he stated: “one universal power, the Roman empire, arose and flourished, while the enduring and implacable hatred of nation against nation was now removed: and as the knowledge of one God, and one way of religion and salvation, even the doctrine of Christ, was made known to all mankind; so at the self-same period, the entire dominion of the Roman empire being vested in a single sovereign, profound peace reigned throughout the world. And thus, by the express appointment of the same God, two roots of blessing, the Roman Empire, and the doctrine of Christian piety, sprang up together for the benefit of men…two mighty powers, starting from the same point, the Roman empire, which henceforth was swayed by a single sovereign, and the Christian religion, subdued and reconciled these contending elements. Our Saviour’s mighty power destroyed at once the many governments and the many gods of the powers of darkness, and proclaimed to all men, both rude and civilized, to the extremities of the earth, the sole sovereignty of God himself. Meantime the Roman Empire, the causes of multiplied governments being thus removed, effected an easy conquest of those which yet remained; its object being to unite all nations in one harmonious whole; an object in great measure already secured, and destined to be still more perfectly attained”
THE LEGACY OF CONSTANTINE:
Constantine may not technically be the first truly Byzantine Emperor, however his reign and his policies paved the way for the Late Roman world which spawned Byzantium. His capital, Constantinople, created a political center which would shield the Eastern Roman Empire in it’s darkest days all the way until 1204AD. Enemies which otherwise may have conquered the Empire were stopped at its walls and in the waters around it. His pro-Christian policies paved the way to Christianity being the official state religion of the Roman Empire by the end of the fourth century. The idea of the Roman Emperor as not just the political leader of the Empire but also as head of the Christian world clearly emerged in this time as well, as seen in the work of Eusebius.
Sources:
Eusebius Caesaeriensis – De laudibus Constanti (335AD) https://www.documentacatholicaomnia.eu/03d/0265-0339,Eusebius_Caesariensis,_De_laudibus_Constantini[Schaff],_EN.pdf
John Julius Norwich – Byzantium: The Early Centuries (1988)
Peter Brown – The World of Late Antiquity AD 150-750 (1971)
Timothy Barnes – Constantine: Dynasty Religion and Power in the Later Roman Empire (2011)
H.A. Drake – Constantine and the Bishops: The Politics of Intolerance (2002)
George Ostrogorsky – History of the Byzantine State (Revised Edition, 1969)
AA. Vasiliev – History of the Byzantine Empire (1952)
shadowsofconstantinople.com 
