On the other hand, however, it involves the assumption of so vast an amount of migration, displacement, and other unlikely ethnological processes, that a writer who weighs conflicting probabilities is led to the conclusion that a great historian is more likely to be wrong in the ethnology of countries like Prussia and Poland—countries which could be known to Tacitus only as the interior of Africa can be known to Mr. Hallam or Macaulay—than that, between A.D. 100, and 900, a whole Gothic population, extending from the Niemen to the Elbe, should have been replaced by a Slavonic one, without leaving a single trace of its existence in any intermediate locality; the same encroaching Slavonians, when we first find them mentioned by cotemporary historians, being themselves in a state of displacement by the same previously-displaced Germans.
This, however, is but a very general and superficial view of the difficulties that attend the belief that the Oder and Vistula were originally German. Nevertheless, it is all that room can be found for here.
As to the tribes themselves the chief were—
The Wagrians.—Occupants of the country between the Trave and the upper portion of the southern branch of the Eyder.
The Polabi.—Conterminal with the Wagrians and the Saxons of Sturmar, from whom they were separated by the river Bille.
The Obodriti.—This is a generic rather than a specific term. It means, however, the tribes between the Trave and the Warnow; chiefly along the coast. Zeuss makes Schwerin their most inland locality.
Varnahi.—This is the form which the name takes in Adam of Bremen. It is also that of the Varni, Varini and Veruni of the classical writers; as well as the Werini of the Introduction to the Leges Anglorum et Werinorum, hoc est Thuringorum.
Linones.—Luneburg. Language spoken during the last century. Known through a pater-noster. Slavonic, modified by German.
Such are the chief western Slavonians of the time of Charlemagne. If they were not also the western Slavonians of the first and second centuries, they must have emigrated between the two periods;[190] "must have done so, not in parts but for the whole frontier; must have, for the first and last time, displaced a population which has ever been the conqueror rather than the conquered; must have displaced it during one of the strongest periods of its history; must have displaced it everywhere, and wholly; and (what is stranger still) that not permanently—since, from the time in question, these same Germans, who, between A.D. 200 and A.D. 800, always retreated before the Slavonians, have from A.D. 800 to A.D. 1800, always reversed the process, and encroached upon their former dispossessors."