The ancient boundary between the Roman Empire and Germany was restored, but at a cost which the former could not pay a second time. For a hundred and fifty years longer the Emperors preserved their territory: Rome still ruled, in name, from Spain to the Tigris, from Scotland to the Desert of Sahara, but her power was like a vast, hollow shell. Luxury, vice, taxation and continual war had eaten out the heart of the Empire; Italy had grown weak and was slowly losing its population, and the same causes were gradually ruining Spain, Gaul and Britain. During this period the German tribes, notwithstanding their terrible losses in war, had preserved their vigor by the simplicity, activity and morality of their habits: they had considerably increased in numbers, and from the time of Marcus Aurelius on, they felt themselves secure against any further invasion of their territory. Then commenced a series of internal changes, concerning which, unfortunately, we have no history. We can only guess that their origin dates from the union of all the principal tribes under the lead of the Marcomanni; but whether they were brought about with or without internal wars; whether wise and far-seeing chiefs or the sentiment of the people themselves, contributed most to their consummation; finally, when these changes began and when they were completed--are questions which can never be accurately settled. [Sidenote: 250--300. GERMAN NATIONALITIES.] When the Germans again appear in history, in the third century of our era, we are surprised to find that the names of nearly all the tribes with which we are familiar have disappeared, and new names, of much wider significance, have taken their places. Instead of twenty or thirty small divisions, we now find the race consolidated into four chief nationalities, with two other inferior though independent branches. We also find that the geographical situation of the latter is no longer the same as that of the smaller tribes out of which they grew. Migrations must have taken place, large tracts of territory must have changed hands, many reigning families must have been overthrown, and new ones arisen. In short, the change in the organization of the Germans is so complete that it can hardly have been accomplished by peaceable means. Each of the new nationalities has an important part to play in the history of the following centuries, and we will therefore describe them separately: 1. THE ALEMANNI.--The name of this division (_Allemannen_,[A] signifying "all men") shows that it was composed of fragments of many tribes. The Alemanni first made their appearance along the Main, and gradually pushed southward over the Tithe-Lands, where the military veterans of Rome had settled, until they occupied the greater part of South-western Germany, and Eastern Switzerland, to the Alps. Their descendants inhabit the same territory, to this day. [A] _Allemagne_ remains the French name for Germany.