The Rise of Kingdoms in the Roman Empire: Part VIIWhen the Byzantine Period began can be debated and is a modern term, anyway. The ancient people of the Empire, whether Byzantine or western, called themselves Romans. The 330s when Constantine built up the new capital city in the East on the site of Byzantium is one date for the starting; the splitting of the Roman Empire into East and West in 395 is another. In the West, however, this was still part of the Imperial period. S. Thomas Parker adds the battle between Constantine and Licinius in 324, as a possible date because that is when Constantine gained control of the eastern empire. The ending date of 1453 is clearer.
Challenges the Roman Emperors Faced
The Germans and the Gauls were just two labels of so-called barbarian, sometime enemies of the Romans. In addition to the names of small tribes like the Tervingi and Greuthungi, there were larger groups of allied tribes that have been labeled as Huns, Alans, Suevi, Alamanni, Burgundians, Franks, Vandals, and Goths, both Visigothic and Ostrogothic, some of which migrated westward and south from their homelands. The first tribes doing the pushing may have been from the Eurasian Steppes. This is according to the prevailing theory of "Völkerwanderungen." (It should be remembered that barbarian was a term to disparage the outsider, but that over the centuries, those who had been barbarians turned into Roman citizens.)
End of Border Expansion
By the end of the second century A.D., Rome was no longer expanding its empire; instead, it had hit upon what was probably a wise policy of trying to keep what it already had, even though Emperor Commodus (r. 177-192) was blamed for not trying to enlarge Rome. With troops now mostly stationed at the frontier, borders remained fairly constant until the fifth century, although there were many skirmishes and territory was lost. Soldiers settled in the areas they were stationed, raising families, and marrying -- after the ban against doing so was lifted, in A.D. 197, by Emperor Septimius Severus. Barbarians might become citizens or serve as Roman auxiliaries; other barbarians fought as mercenaries. Paying the military strained the emperor's resources already strained by trying to maintain safety at the empire's borders.
Honoring the Emperor
The emperor, a term that comes from the word Roman soldiers used to acclaim their victorious commander -- Imperator, didn't always lead his troops himself, although emperors had commands of armies and the 30 legions ' worth of soldiers swore allegiance to their emperors at least once a year at the annual January 3 sacramentum [Constantine, p.16]. He was also at the head of a growing civil bureaucracy. His accroutrements were increasingly regal, from the time of Diocletian, emperor from 284, and the Tetrarchy, when Romans were first required to prostrate themselves before the emperor, a custom adopted from eastern absolute monarchs and previously considered too degrading for free citizens. They also started wearing the diadem and elaborate purple robes.
The growing bureacucracy kept the emperor apart from his people and allowed him to compartmentalize the Empire. This could be efficient or a source of trouble, depending on how well the emperor could oversee and understand what was going on in all parts of his empire. Age factored in, as younger emperors or emperors under the control of regents couldn't be counted on to make wise choices when the ambitions and prejudices of their advisors counted more than Rome's welfare. The historian Zosimus, who is the first to write about the fall of Rome, says the following about two of the emperors at the time of the removal of Roman troops from Britain, and more crucially for the Fall of Rome, the 410 sack of Rome by Alaric and the Visigoths.
The whole empire being vested in Arcadius and Honorius, they indeed appeared by their title to possess the sovereign authority, although the universal administration of affairs was under Rufinus in the east, and under Stilico in the west. By these all causes were determined, at their own pleasure; for whoever bribed plentifully, or by any other means of friendship or consanguinity could make the judge his advocate, was sure to succeed in the process. From hence it happened that most of those great estates, which cause the possessors to be generally esteemed fortunate, devolved to these two; since some endeavoured by gifts to avoid false accusations, and others relinquished all their possessions to obtain an office, or in any other manner to purchase the ruin of particular cities. While iniquity of every kind presided, therefore, in the respective cities, the money from all quarters flowed into the coffers of Rufinus and Stilico ; while on the reverse, poverty preyed on the habitations of those who had formerly been rich. Nor were the emperors acquainted with anything that was done, but thought all that Rufinus and Stilico commanded was done by virtue of some unwritten law.
Zosimus, New History. London: Green and Chaplin (1814). Book 5.
Military bureaucrats handled assignment of troops to the hot zones; civil bureaucrats dealt with all the non-military details of a regal court. In the following section, you'll find the principal division of the Roman Empire in the later period, plus some of the major officers.
The Rise of Kingdoms in the Roman Empire Part1 - Ancient History: From Prehistory to the Early Middle Ages
2 - Other Dates for Rome's Fall: Pros and Cons
3 - How the Romans Handled Problems of Imperial Successions
4 - The Barbarian at the Gates
5 - Early Rome and the Issue of Kings
6 - Caesar's Role in the Collapse of the Roman Republic
7 - Challenges the Empire Faced and Resolved by Division
8 - Administrative Units of the Later Roman Empire
9 - Kings Replace the Roman Emperor