You will see now what the story told in the first few chapters of this volume is, for the most part, about. It is about the efforts of the Empire--on the whole, the successful efforts of the Empire--to keep itself intact within its walls and to keep the barbarians out. The pressure of those barbarians without, together with the weakened state of the Empire itself, has led to the division of the Eastern from the Western Empire. And that is the story up to close on the year 400. After that year 400, or a few years before, the story changes. It is no longer about the efforts of the Empire to keep the barbarian out. The barbarian is triumphantly breaking through; and it is with that break through, and with all that happened to the Empire, as a consequence, that the story has now to deal. We shall think it curious, as we follow it, to note how the different tribes of the barbarians seem as if they acted together, in concert with each other, from the northern extremity of the Empire's boundary right down to where we saw those Visigoths permitted to settle south of the Danube. They seem to have pressed in from the east, within the space of very few years, along the whole of that boundary. Probably it was by no pre-concerted arrangement, that is to say not following any already arranged {31} plan, that they pressed in along that boundary nearly all at the same time. Probably what happened was that all of them were feeling a pressure from the Huns, their neighbours on the east: so that they were all ready to move. Then, when one tribe heard of the success of another in moving west, the tribe that heard this news would be encouraged to attempt a westward push on its own account. That push would be all the more likely to succeed because the Roman legions were busy trying to stop those that had moved westward already. [Sidenote: British legions re-called] To what extent they acted together in order to help each other we do not know--probably with very little idea of giving each other this help, for often when they encountered each other in the course of the westward move, they actually fought amongst themselves. What we do know--and it is a fact that made a great difference to the story of our own islands--is that within a very short time the Empire found its legions so hard beset on the Continent of Europe that it recalled the three legions that had been holding Britain. This happened in 407.