All these peoples, of whom it is convenient to speak by the Roman term of barbarians, were of the great family of mankind that is called the Indo-European—that is the more general name, including them all, of which I wrote a few pages back. It is given that name, because some of the family went south, into India, and some west, into Europe, out of some region in the north and east, which seems to have been a great hive or nursery of mankind out of which we came swarming south and west.

This hive seems to have had its home perhaps in the west of Russia; but little is known about it. Probably it would be more right to speak of many hives, scattered over a large region, than of one. But we may know that the scattered members of the family—those in India and those in Europe—are related by the similarity of some of the most common words, or parts of words, in the languages of India and of those lands of which the European members of the family got possession.

Besides its troubles from the threats of these barbarians on its north-west borders, the Empire, as we have seen, had its troubles through most of this century from Persians and others on the south-east; and I now want to ask you to notice an effect of these troubles and threats of trouble on the Empire itself, for it was an effect which made a very great difference to the story. This effect was the dividing up of the one Empire into two, with a Western Empire, as of old, having its seat of government at Rome; but also with an Eastern Empire having its centre of government at Byzantium, as Constantinople was then called.

CHAPTER IV
THE DIVISION OF THE EMPIRE

The causes that led to the dividing up of the Empire are easily understood. What is far less easy to understand is how Rome ruled the world, as the world then was known, so long as she did. Remember this: at that time you could only travel, and you could only send a message, as fast as a horse could gallop, if it was by land that you went or sent; and only as fast as a ship—a ship with a very simple and primitive way of setting the sails—could be urged through the water by sailing or by rowing, if your going was by sea. For practical purposes of getting news or of moving troops, the world of the Romans of that date, say from Egypt to Britain at its furthest points, was a very great deal larger than the whole of the globe is to us to-day. If you can understand it in that sense, their Empire was very much larger, much less under the eye and the direction of the centre of government, than the whole British Empire to-day. And we find that large enough. The Romans had the further trouble, which we have not, that the leaders of the legions in the provinces, when they had repelled the barbarians, sometimes claimed to be independent of the central authority, as we saw both in Gaul and in Asia Minor.

So the wonder really is, not that Rome should at length fail to govern all this Empire from one centre, but that she should have succeeded in doing so at all, and for so long. From causes which I have spoken of already, the home government was not as strong as it had been; and as the power at the centre grew less the pressure of the barbarians on the boundaries grew more. Especially it became convenient to have a centre of government nearer the boundary on the south-east, where the eastern barbarians were constantly making their attacks and where a great leader of the army, if he checked the attack, might become too strong for the authority of Rome to control unless it put forth all its force. A solution of the trouble was attempted by the Emperor Diocletian, who came to the imperial throne in 284. What he did was to appoint a colleague for himself to whom he gave his own title of Augustus, though he also retained the title for himself. There were, therefore, two Augusti. And besides the Augusti, he appointed two leaders of armies in the provinces to bear the title of Cæsar. Thus there were two Cæsars and two Augusti. The Empire and its armies were portioned out between these four great persons. Diocletian himself had the command of the army of Syria. His colleague, the other Augustus, commanded the armies of Italy and of Africa. One of the Cæsars had the armies guarding the Rhine, and the other the armies guarding the Danube boundary.

In this way were the Empire and its defending forces divided up. The Cæsars were considered to be in an inferior position to the Augusti, and as between the Augusti themselves Diocletian was supposed to to be the superior of the other. We may think it likely that the Emperor, in making these appointments, did little more than give his formal approval to arrangements that already existed, in fact. Very probably these important persons would have been able to make themselves practically independent of the Emperor, even if he had not given them these offices, and very likely they were the more ready to pay him some show of deference because he had given them his approval.

There is one point about the arrangement to which I would call your attention, and that is that Diocletian, who claimed to be the superior of them all, assumed, for his own command, the army of Syria, of the East. You will perceive what that seems to indicate—that the Romans had begun to look upon the Eastern side of the Empire as more important than the Western. As early as the year 300, or even earlier, this was their view.