Byzantium under the Constantinian and Valentinian dynasties

Byzantium under the Constantinian and Valentinian dynasties was the earliest period of the Byzantine Empire that saw the creation of an eastern Empire from the Roman Empire under the emperor Constantine I in his new capital, Constantinople, formally named Nova Roma, created on the site of the old Greek Byzantium. Constantine's successors ruled over portions of the empire in Egypt, Syria, and the Balkans.

Economic strife[edit]

Further information: Crisis of the Third Century

In the 3rd century, the Roman Empire suffered troubling economic difficulties that spread over a wide portion of its provinces. Drastic decreases in population throughout the western parts of the Empire, along with a general degradation of society within the cities exacerbated the crisis, leading to a shortage of labor. The latifundia, or great estates, added to the troubles by forcing many of the smaller estates out of the market, which bled more labor from the labor force in order to sustain their estates. In the East, although there was a labor shortage, the population problem was not nearly as acute, rendering it stronger and more able to withstand a serious crisis.^[1] The West, in its reaction to the economic hardships that resulted in very high prices, had gone to abarter system to survive. In contrast, the East had chosen to depend upon gold coinage for the most part, creating a very reliable means by which to sustain itself.^[2]

Administrative reforms[edit]

The Roman emperors Diocletian and Constantine I both played an important role in reforming the organization of the whole Empire. The Empire in its entirety had become difficult to control, and Diocletian resolved this by creating a tetrarchy that allowed for Augusti to rule in each of the western and eastern halves of the Empire, while two Caesars would be their seconds. In case of the loss of either Augusti, the Caesar would take their place, and a new Caesar would be selected. The only significant change made by Constantine to this system was the replacement of the selection of Caesars with a succession by bloodline.^[3]

To alleviate the concerns of territorial administration, Diocletian divided the whole of the Empire into one hundred distinct provinces. Administrative control was brought under the auspices of the Emperor, and the whole of Italia was relegated to the status of a regular province, now also compelled to pay taxes. Each province was subdivided into a diocese, twelve in total. Constantine organized the provinces even further by creating prefectures, each one consisting of several dioceses, and each diocese consisting of several provinces. The Praetorian prefecture of the East(Praefectura praetorio per Orientem) was made up of five dioceses- Aegyptus, Oriens, Pontus, Asiana, and Thracia. This enabled the Empire to harness the control of each prefecture by providing a distinct difference between military and civil administration.^[4]

Military threats and the division of the Empire[edit]

Focus from the West to the East had been shifting over the course of the last century due to previously mentioned economic strength of the usage of gold coinage and a stronger populace. The defensive situation under Diocletian, however, had changed considerably in the East. The Persian Sassanids had grown more menacing in their quest for previous territory, and the barbarians were becoming a more serious problem along the lower part of the Danube. Judging the threats to be of dire importance, Diocletian took up residence in Nicomedia, where he established his capital there, leaving Maximian, his co-Emperor, in charge of the West.^[