In the third century the Empire was declining. This was due not only to external troubles, such as wars with the new Persian Empire which had arisen in the east, but much more to internal dissensions and disruptions, civil wars and contests for the imperial throne. The central government had become weak and almost bankrupt; the various parts of the Roman world were showing tendencies to fall asunder and to set up rulers of their own. One of the most significant symptoms of decay was the depeciation of the coinage.
This state of things was ended by two great Emperors, Aurelian, who obtained the supreme power in 270, and Diocletian, who ascended the throne fifteen years later (285) and reigned for twenty years till 305. In the generation -thirty-five years- which elapsed between the accession of Aurelian, who rescued the Empire at the brink of an abyss, and the end of Diocletian’s reign, the administration, the army, and the finances were reorganised. After Diocletian’s abdication of power in 305, there were twenty years of trouble -struggles for power among his successors, at the end of which (324) one of the most notable figures in the history of the world, Constantine the Great, emerged victorious.
The work of these sovereigns completely renovated the Empire; and up to the end of the fourth century it enjoyed a series of able and hard-working rulers who preserved its frontiers virtually intact. There is a striking historical fact which illustrates how the Empire recovered. It relates to the reform of the currency. A new gold standard was introduced by Constantine. Constantine coined 72 gold pieces to the pound weight. This gold piece was called an aureus or a solidus. This standard gold coin was issued from his time up to the eleventh century, by the imperial mints, without any depreciation.
In the third and fourth centuries the Roman Empire extended from the Tyne to the Euphrates. It included all the lands now known as England and Wales, France, Spain, Italy and Switzerland, Austria and Hungary, the Balkan peninsula, Asia Minor and Syria, and the whole coast lands of North Africa from Egypt to Morocco.
The history of the third century, as already remarked, showed the natural tendency of the parts of this huge heterogeneous empire to fall asunder. The principal line of division was a language line -to the west of which line Latin was spoken generally, and to the east, Greek. Thus the Empire fell naturally into two great sections -a western or Latin section and an eastern or Greek section. This, of course, does not mean that other languages were not spoken too. Coptic was spoken in Egypt, Aramaic in Syria, Celtic tongues in Britain and parts of Gaul, and so on: it means that in the eastern section Greek was the prevailing tongue and the general language of intercourse, and in the western, Latin. The Emperor Diocletian was convinced that the Empire was too huge to be centralised under one sole ruler, and so he made a scheme to place it under two coequal emperors, one ruling the Western section, and the other the Eastern; each of them to be assisted by a subordinate, or lieutenant, who had not the full imperial title of Augustus, but only the lower title of Caesar. I need not enter upon the details of the scheme, which was highly artificial and remarkably unsuccessful; for it was abandoned by Constantine. But it involved a new imperial centre of government in the east, as well as at Rome; and this led to the great and decisive act of Constantine in establishing a second Rome at Constantinople, A.D. 330.
This division of the Empire into two parts, one mainly Latin, the other mainly Greek, lasted for 150 years; it was for the greater part of that time ruled by two emperors, occasionally it was under one. But throughout all this period there were the two seats of government, one at the old Rome on the Tiber, the other at the new Rome on the Bosphorus; and the two governments, their systems, their organisations, their officials were exactly the same; one was virtually the replica of the other. That was a very remarkable, indeed a unique, experiment in government; an empire ruled not from one centre, but from two foci, through two parallel organisations. The two parts are often loosely spoken of as if they were two distinct Empires -the eastern and the western. That is a mistake against which we must be on our guard. The unity of the two parts was always most carefully maintained. The Roman Empire was always considered one and indivisible. It never entered anyone’s head to think of two. The unity was maintained and expressed in various ways, particularly in legislation. When a law was passed at Constantinople, it was issued not merely in the name of the emperor who was ruling there but in the joint names of him and the emperor ruling in the west; and conversely. The old practice of appointing two consuls at the beggining of every year was preserved, and one of them was nominated at Rome and the other at Constantinople.
The renovated Empire received a new organisation, the result of reforms partly due to Diocletian and partly to Constantine. The general result was that for the purposes of civil administration the whole Empire fell into four great sections, two in the west and two in the east, known as prefectures, because each section was governed by a great minister entitled a praetorian prefect, who was responsible solely to the Emperor. The two western prefectures were the Gauls and Italy, but each of these included many lands which we do not now associate with those names. The Prefecture of the Gauls included, as well as Gaul, Britain and Spain and the north-west corner of Africa -Morocco. The Prefecture of Italy included, as well as Italy, Switzerland and the provinces between the Alps and the Danube, and also the coast lands of North Africa. The two eastern prefectures were the Prefecture of Illyricum, which covered the Balkan peninsula, with the exception of Thrace, and was the smallest of the four; and the Prefecture of the Orient, which comprised of Thrace and Egypt, and all the Asiatic territory that belonged to the Empire.
Each of these prefectures was divided into large districts called dioceses, each of the size of a fair-sized modern state. Thus in the prefecture of the Gauls there were four dioceses: Britain, two dioceses in Gaul, and Spain. And in each diocese was under a vicar, who was subject to the praetorian prefect. And in each diocese there were a number of provinces each under a provincial governor. Thus the whole system of civil government was, roughly speaking, a hierarchy, like a ladder, with the Emperor at the top, the provincial governor at the foot, and the praetorian prefects and the vicars as the intermediate steps -roughly speaking, for there were a number of exceptions and complications which we need not trouble about. For our present puprose what I have said is enough respecting the civil organisation, and its general hierarchical character. Only observe that there are two such systems, two of these hierarchies, one centring at Rome, the other at Constantinople, like two clocks similarly constructed but functioning independently. And it is important to remember that neither of these great civil administrations had any military functions. The separation of civil and military authority was one of the capital features which differentiated the new monarchy of the fourth and following centuries from the earlier empire of Augustus.
It is the military organisation of the Empire which it is of great importance for us to understand, and its German invaders. The principal feature in which the military establishment of the fourth and fifth centuries differed from that of the early Empire was the existence of a mobile army. While all the frontiers were defended by troops permanently stationed in the frontier provinces, distinguished as limitanei, there was also a field army which the Emperor could move to any part of his domain which happened to be threatend whenever war broke out; and these troops, which accompanied the Emperor in his movements and so formed an imperial retinue, or comitatus, were distinguished as comitatenses. Thus the military forces consisted of two main classes, the comitatenses, who were the most important when there was serious warfare, and the limitanei.
A second outside feature in the military organisation of the later Empire is the smaller size of the legionary unit. The strength of the old Roman legion, as it had hitherto been, was about 6000 men; and it was associated with a number of cohorts of infantry and squadrons of cavalry, all under the command of the legatus or commander of the legion, so that the legatus had about 10,000 men under him. All this is changed. The old legion of 6000 is broken up into detachments of 1000; new legions that are formed are only 1000 strong; the cohorts and the cavalry squadrons are under separate commanders.
Most important is the separation of the cavalry from the infantry, and its conversion into an independent arm instead of a subordinate one. All these armies were under the supreme command of Masters of Soldiers, Magistri Militum. It is usual to translate this term literally; they correspond in rank to what we call Field-Marshals, but they had definite commands, and here the systems in the west and in the east developed rather differently.
In the east there were five Masters of Soldiers. Two of these resided at Constantinople and commanded the troops of the field armies stationed in the immediate neighbourhood of the capital. They were distinguished as Magistri in praesenti, i.e. in immediate attendance on the Emperor. The other three were stationed in the large districts of the east, Thrace, and Illyricum respectively, and commanded the troops stationed in them.
In the west it was different. Here we do not find co-ordinate commanders, but two, magistri militum in praesenti, whose headquarters were in Italy; one was commander of the infantry, magister peditum, the other of the cavalry, magister equitum. But though nominally co-ordinate, the first, the Master of Foot, was much the more important. He had supreme authority not only over the mobile infantry of the west, but also over the commanders of infantry of the west, but also over the commanders of the limitanei. Towards the end of the fourth century he acquired superior authority over his colleague the Master of Horse, and thus supreme command of all the military forces of the west, and received the title magister utriusque militiae, Master of Both Services, i.e. both infantry and cavalry.
This difference in organisation had grave political results. In the west the concentration of military power in the hands of one man made the Master of Both Services the most important and influential minister, the man who really directed the policy of the state, and from the close of the fourth century up to the time when the western half of the Empire had completely passed into the power of the Germans, not only the defence of the Empire but the general management of its affairs was in the hands of a succession of soldiers, Masters of Both Services, who were sometimes a danger to the throne. In the east, on the other hand, there are a few cases, but not many, in which the Master of Soldiers attained to undue power.
It might seem surprising at first to find that the total fighting forces of the Roman Empire (with a population of 55-70 million) never reached 1 million. To explain this the first thing to observe is that in the old civilised countries round the Mediterranean Sea the population had become quite useless for military service. They were too highly civilised, and not physically fit enough, on the average, to do hand-to-hand fighting with the uncivilised barbarians. Thus, large parts -and the most populous parts- of the Empire are practically withdrawn from our calculation, for they contributed almost nothing in the form of fighting men to the military strength of Rome. So far did this go that in the end it may be said that the only provinces in the interior of the Empire which furnished a constant supply of recruits were the highlands of the Balkan peninsula and the mountainous regions of Asia Minor, for instance Isauria. Otherwise, the army was chiefly recruited from frontier provinces, where there was a population with a large barbarian admixture.
In the third century the army was very largely Illyrian. Diocletian and Constantine both belonged to families of the Balkan peninsula which had risen through military service. In old days foreigners used to be excluded from military service; it was confined to Roman citizens. But at the end of the third century this was given up; foreigners from beyond the limits of the Empire were freely admitted as recruits; while at the same time the principle of the universal liability of citizens was abandoned in practice.
There were four classes of recruits, i.e. four sources from which they were drawn.
1. The sons of soldiers: military service was hereditary and the son was bound to follow his father’s profession.
2. Serfs: it was a state burden on landed proprietors to supply a certain number of recruits from among their serf tenants.
3. Barbarian settlers: some troops were supplied from the communities of foreign barbarians who were settled in some provinces, especially in east Gaul and north Italy.
4. Adventurers: the most important source of supply was the numerous poor adventurers, both native and foreign, who voluntarily offered themselves to the recruiting officers. Of these adventurers the barbarian volunteers were the most useful and efficient. The Germans who came to enlist, attracted by the pay and the prospect of a career, gradually replaced the Illyrians as the predominant element in the army. Under Roman drill and discipline they became excellent soldiers and rose rapidly to officer rank. Very many of the soldiers who held the highest posts in the last part of the fourth century were of German origin. This is an exceedingly important point. There was in fact a process of Germanisation going on during that century, and it constituted a grave danger. Looking back we can see that the Emperors adopted too liberal a policy in allowing Germans to occupy posts of supreme command. This liberality was due to the desirability of attracting the best men to a career in the imperial service; the Emperor Constantine always showed marked favour to Germans, and Julian reproached him for pampering them. German customs (e.g. of elevating an emperor on a shield) made way in the army. The general result was that from the end of the first quarter of the fourth century the German star was gradually rising.
(Source: “The Invasion of Europe By the Barbarians”, by Bury, J.B.)
Research-Selection for NovoScriptorium: Anastasius Philoponus